(Adds comments by Missouri department of corrections)
By Carey Gillam
Sept 3 (Reuters) - Missouri officials have not been truthful about the drugs and methods used in recent executions, misleading lawyers for death row inmates and the public, according to a St. Louis Public Radio investigation broadcast on Wednesday.
The report, based on court records and other documents, showed that while Missouri officials have said publicly and in court records that they only use one drug, pentobarbital, to put prisoners to death, the state has also been using a controversial sedative called midazolam in every execution since November 2013.
In all nine executions since then, Missouri's execution team has injected inmates set to die with significant amounts of the sedative before using the pentobarbital, it said. The report was broadcast and published online http://bit.ly/1cj1ZoS.
The use of midazolam is under scrutiny nationwide after inmates in botched executions in Ohio, Oklahoma and Arizona were given the drug and took longer than is typical to die, showing signs of distress.
"This goes beyond hiding things. This is an issue of them deliberately misleading the (inmates), the lawyers, the courts and the general public," said Kathryn Parish, a lawyer representing Missouri inmate Earl Ringo, who is scheduled to be put to death on Sept. 10.
Parish said she and other lawyers for Missouri death row inmates would be filing court action based on the public radio report.
Oral arguments are set for Sept. 9 in a long-running lawsuit filed by more than a dozen Missouri death row inmates against the state over its lethal injection protocols.
Missouri Department of Corrections spokesman David Owen said sedatives administered are not part of the execution process. They are given prior to the start of the execution, he said.
"Executions are conducted by the Department of Corrections pursuant to an execution protocol that has been reviewed numerous times by the court," said Owen in a statement. "That protocol provides for the use of sedatives in advance of the execution."
The radio report said that corrections officials in at least one case appear to have given midazolam 30 minutes before the inmate's execution warrant was valid.
Joseph Luby, another lawyer who represents death row inmates in Missouri, said the report underscores the depths of Missouri's secrecy.
"The state shouldn't be carrying out executions when we don't know exactly what drugs the state is administering, where they come from, and by whom and how they are made," said Luby.
Missouri and other states have been struggling to secure adequate lethal injection drugs for more than a year, after major drug companies objected to their products associated with executions.
Many states have turned to compounding pharmacies to procure the drugs, and Missouri has been particularly secretive about its protocols, refusing to say where it gets its supply.
Lawyers for death row inmates argue that compounding pharmacies are poorly regulated, giving no assurances that the drugs they produce are potent and pure, and that inmates could suffer tortuous deaths that violate the U.S. constitution. (Reporting by Carey Gillam in Kansas City; Editing by Susan Heavey and Cynthia Osterman)