* Red Bull says blackmailers threaten to taint drinks
* No evidence so far that drinks actually contaminated
* Says went public to remove extortionists' leverage
* Prosecutors focus on Austria, work with Germany (Adds comment from prosecutors)
VIENNA, March 14 (Reuters) - The beverage and sports marketing giant Red Bull said on Thursday it was the target of a blackmail attempt by someone who had threatened to contaminate its energy drinks.
The extortionists had threatened to taint beverage cans with faecal matter if they were not paid off. Checks at stores where they said they had put contaminated drinks had found nothing, Austria-based Red Bull said.
"Someone has been trying to blackmail Red Bull for weeks," Red Bull said in a statement, adding it went public with the information in order to neutralise the blackmailers' leverage.
"We are cooperating closely with police and share the opinion that we are close to the perpetrators and they will be found," it said, adding that it would make no further comment while the investigation continued.
Police in Salzburg, where Red Bull is based, had no comment.
"We know the facts - the text that Red Bull has published - and cannot say anything more," a police spokesman said.
Salzburg prosecutors have been investigating the threat since the beginning of March, spokesman Marcus Neher said. "So far, we have not found a single case of contamination," he said.
He said their investigations were focused on Austria but they were also working with prosecutors in Germany. He declined to comment on Red Bull's statement that they believed they were close to finding the perpetrators.
Red Bull's co-founder, Dieter Mateschitz, has a net worth of $7.1 billion, making him Austria's richest person and number 162 in the world, according to Forbes magazine. Red Bull sales grew 12 percent in 2011 to $5.6 billion, according to Forbes.
The private company, whose products are especially popular with young people, is known for its elaborate marketing and association with extreme sports.
It scored a coup last year when it sponsored daredevil Felix Baumgartner's record-breaking skydiver from the edge of space. Its world champion Formula 1 motor racing team opens the season on Sunday. (Reporting by Michael Shields, Fredrik Dahl and Georgina Prodhan; Editing by Michael Roddy)