AUSTIN, Texas — For Lance Armstrong, the doping allegations aren't going away. In fact, they're starting all over again.

The U.S. Anti-Doping Agency has filed formal charges against the seven-time Tour de France winner, threatening to strip him of his victories in the storied cycling race.

Armstrong, who forcefully denied the accusations, could face a lifetime ban from the sport if he is found to have used performance-enhancing drugs. The move by USADA immediately bans him from competing in triathlons, which he turned to after he retired from cycling last year.

Armstrong has been dogged by doping allegations since his first Tour victory in 1999, but had hoped his fight to be viewed as a clean champion was finally won after U.S. federal prosecutors closed a two-year criminal probe in February without bringing any charges. Armstrong has said the investigation took a heavy emotional toll and he was relieved when it ended.

But USADA officials insisted they would continue to pursue their own probe into Armstrong and his former teams and doctors, and notified him of the charges in a 15-page letter on Tuesday. Unlike federal prosecutors, USADA isn't burdened by proving a crime occurred, just that there was use of performance-enhancing drugs.

In its letter, USADA said its investigation included evidence dating back to 1996. It also included the new charge that Armstrong blood samples taken in 2009 and 2010 are "fully consistent with blood manipulation including EPO use and/or blood transfusions." Armstrong came out of his first retirement to race in the Tour de France those two years.

Armstrong, who was in France while training for a triathlon, issued a statement dismissing the latest allegations "baseless" and "motivated by spite." Even though he last won the Tour seven years ago, the 40-year-old Armstrong remains a popular – if polarizing – figure, partly because of his charity work for cancer patients.

USADA's letter also said the agency was bringing doping charges against Johan Bruyneel, manager of Armstrong's winning teams; team doctors Pedro Celaya and Luis Garcia del Moral; team trainer Pepe Marti, and consulting doctor Michele Ferrari.

The USADA letter, a copy of which was obtained by The Associated Press, accuses Armstrong of using and promoting the use of the blood booster EPO, blood transfusions, testosterone, human growth hormone and anti-inflammatory steroids. The letter doesn't cite specific examples, but says the charges are based on evidence gathered in an investigation of Armstrong's teams, including interviews with witnesses who aren't named.

Cycling's governing body, the International Cycling Union, which collected the 2009 and 2010 samples cited in the USADA letter, said it was not involved in the anti-doping group's investigation.

According to USADA's letter, more than 10 cyclists as well as team employees will testify they either saw Armstrong dope or heard him tell them he used EPO, blood transfusions, testosterone and cortisone from 1996 to 2005. Armstrong won the Tour de France every year from 1999-2005.

During their investigation, federal prosecutors subpoenaed Armstrong supporters and ex-teammates to testify in Los Angeles. One of the most serious accusations came during a "60 Minutes" interview when former teammate Tyler Hamilton said he saw Armstrong use EPO during the 1999 Tour de France and in preparation for the 2000 and 2001 tours.

Early in the criminal investigation, Armstrong attorney's accused USADA of offering cyclists a "sweetheart deal" if they testify or provide evidence against Armstrong.

In a letter to USADA last week, Armstrong attorney Robert Luskin noted that USADA Chief Executive Officer Travis Tygart participated in witness interviews with federal investigator Jeff Novitzky during the criminal probe.

"It is a vendetta, which has nothing to do with learning the truth and everything to do with settling a score and garnering publicity at Lance's expense," Luskin wrote.

In a statement, Tygart said, "USADA only initiates matters supported by the evidence. We do not choose whether or not we do our job based on outside pressures, intimidation or for any reason other than the evidence."

Armstrong has until June 22 to file a written response to the charges. The case could ultimately go before an arbitration panel to consider evidence. The USADA letter said in that case a hearing should be expected by November.

Armstrong, maintained his innocence, saying in his statement: "I have never doped, and, unlike many of my accusers, I have competed as an endurance athlete for 25 years with no spike in performance, passed more than 500 drug tests and never failed one. ...

"Any fair consideration of these allegations has and will continue to vindicate me."

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  • Lance Armstrong, Floyd Landis

    In this July 24, 2004, file photo, overall leader Lance Armstrong, right, of Austin, Texas, follows compatriot and teammate Floyd Landis, left, in the ascent of the La Croix Fry pass during the 17th stage of the Tour de France cycling race between Bourg-d'Oisans and Le Grand Bornand, French Alps.

  • Lance Armstrong

    Lance Armstrong negotiates the route on the way to his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from professional cycling.

  • Lance Armstrong

    FILE - In this Feb. 15, 2011, file photo, Lance Armstrong pauses during an interview in Austin, Texas. Armstrong said on Thursday, Aug. 23, 2012, that he is finished fighting charges from the United States Anti-Doping Agency that he used performance-enhancing drugs during his unprecedented cycling career, a decision that could put his string of seven Tour de France titles in jeopardy. (AP Photo/Thao Nguyen, File)

  • ARMSTRONG

    FILE - This July 25, 1999 file photo shows Tour de France winner Lance Armstrong being kissed by his wife Kristin, left, and his mother Linda after the 20th and final stage of the Tour de France cycling race in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Laurent Rebours, File)

  • Lance Armstrong

    FILE - In this July 6, 2010, file photo, Lance Armstrong grimaces prior to the start of the third stage of the Tour de France cycling race in Wanze, Belgium. Armstrong said on Thursday, Aug. 23, 2012, that he is finished fighting charges from the United States Anti-Doping Agency that he used performance-enhancing drugs during his unprecedented cycling career, a decision that could put his string of seven Tour de France titles in jeopardy. (AP Photo/Christophe Ena, File)

  • ARMSTRONG JALABERT MC EWEN

    FILE - This July 28, 2002 file photo shows Tour de France winner Lance Armstrong, center, flanked by best sprinter Robbie McEwen, of Australia, right, and best climber Laurent Jalabert, of France, after the 20th and final stage of the Tour de France cycling in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Peter Dejong, File)

  • ARMSTRONG

    FILE - This July 23, 2000 file photo shows Tour de France winner Lance Armstrong riding down the Champs Elysees with an American flag after the 21st and final stage of the cycling race in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Laurent Rebours, File)

  • Lance Armstrong

    FILE - In this Feb. 28, 2011, file photo, former cycling champion Lance Armstrong smiles during a news conference at the Cedars-Sinai Hospital in Los Angeles. The U.S. Anti-Doping Agency on Wednesday, July 11, 2012, granted Armstrong an extension of up to 30 days to contest drug charges while the seven-time Tour de France winner challenges the case in federal court. (AP Photo/Damian Dovarganes, File)

  • Lance Armstrong, Ivan Basso, Jan Ullrich

    FILE - In this July 24, 2005 file photo, Lance Armstrong gestures from the podium after winning his seventh straight Tour de France cycling race, as second-placed Ivan Basso of Italy, left, and third-placed Jan Ullrich of Germany, look on, after the 21st and final stage of the race in Paris. Armstrong, he superstar cyclist whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Christophe Ena, File)

  • Lance Armstrong

    Lance Armstrong, right, chats with other riders at the start line of the Power of Four mountain bicycle race at the starting line in Snowmass Village, Colo., early Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from the sport.

  • Lance Armstrong, Keegan Swirbul

    Lance Armstrong, front, talks to reporters after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. Race-winner Keegan Swirbul, 16, of Aspen, left, clapso his hand.

  • Lance Armstrong

    Lance Armstrong guides his bicycle down the steps after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from professional cycling.

  • Lance Armstrong

    Lance Armstrong listens at the World Cancer Congress in Montreal Wednesday, Aug. 29, 2012.

  • Lance Armstrong

    Lance Armstrong speaks to delegates at the World Cancer Congress in Montreal Wednesday, Aug. 29, 2012.

  • Lance Armstrong

    Lance Armstrong signs autographs for supporters after a run, Wednesday, Aug. 29, 2012, on Mont Royal Park in Montreal.

  • Lance Armstrong

    Lance Armstrong talks to supporters prior to a run, Wednesday, Aug. 29, 2012, on Mont Royal Park in Montreal.

  • Lance Armstrong

    Lance Armstrong competes in the Rev3 Half Full Triathalon Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong

    Lance Armstrong crosses the finish line of the Rev3 Half Full Triathalon Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong, Isabelle Armstrong, Grace Armstrong

    Lance Armstrong crosses the finish line of the Rev3 Half Full Triathalon with his ten-year-old twin daughters Grace, left, and Isabelle, right, Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong

    In this Aug. 25, 2012, file photo, cyclist Lance Armstrong prepares to take part in the Power of Four mountain bicycle race in Snowmass Village, Colo. With U.S. anti-doping officials set to issue their report on Armstrong's case, a lawyer for the cyclist on Tuesday again criticized the process which led to himn being banned from the sport for life.

  • Lance Armstrong

    In this Aug. 25, 2012, file photo, Lance Armstrong considers a question from a reporter after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo.

  • Lance Armstrong

    This April 1, 2012 file photo shows seven-time Tour de France champion Lance Armstrong grimacing during a news conference after the Memorial Hermann Ironman 70.3 Texas triathlon in Galveston, Texas.

  • This is a July 24, 2005, file photo showing overall leader Lance Armstrong, of Austin, Texas, surrounded by press photographers, signaling seven, for his seventh straight win in the Tour de France cycling race, prior to the start of the 21st and final stage of the race, between Corbeil-Essonnes, south of Paris, and the French capital.

  • Lance Armstrong

    This July 5, 2004 file photo shows U.S. Postal Service team leader and five-time Tour de France winner Lance Armstrong, third from right, framed by his teammates as the pack rides during the second stage of the 91st Tour de France cycling race between Charleroi and Namur, Belgium.

  • Lance Armstrong, George Hincapie

    This March 21, 2009 file photo shows Lance Armstrong, of the United States, beside fellow countryman George Hincapie, left, during the Milan-San Remo cycling classic in San Remo, Italy.

  • Lance Armstrong

    Lance Armstrong waits for the start of the Ironman Panama 70.3. triathlon in Panama City, Panama.

  • Lance Armstrong

    This May 11, 2012, file photo shows cycling great and cancer survivor Lance Armstrong at a rally in favor of Proposition 29, at Children's Hospital in Los Angeles.

  • Lance Armstrong

    Lance Armstrong (center) leads the pack coming to Jack's restaurant in Pleasant Grove, Ala., Friday, April 27, 2012,, on the fourth day of the Bo Bikes Bama charity bike ride on the one-year anniversary of the deadly Alabama tornadoes.

  • Lance Armstrong

    From left, Bo Jackson, Lance Armstrong, Picabo Street and Ken Griffey, Jr. gather for a photo as the greeted fans and signed autographs in Pleasant Grove, Ala., Friday, April 27, 2012,, on the fourth day of the Bo Bikes Bama charity bike ride on the one-year anniversary of the deadly Alabama tornadoes. Jackson and about 140 bicyclists and the celebrity bikers rode from Cordova, Ala. to Bessemer, Ala. on Friday.

  • Lance Armstrong

    Lance Armstrong waits for the start of the Memorial Hermann Ironman 70.3 Texas triathlon, Sunday, April 1, 2012, in Galveston, Texas. Armstrong finished in seventh place.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.