(Corrects April 2 story to make clear stay for second inmate active; paragraphs 1, 3 and 8)
By Jon Herskovitz and Heide Brandes
AUSTIN, Texas, April 2 (Reuters) - A U.S. appeals court overturned a temporary stay of execution on Wednesday for a Texas inmate challenging the state's lack of disclosure about the supplier of the drugs to be used in his lethal injection on Thursday.
The decision puts back on track an execution scheduled for Thursday evening that had been suspended temporarily earlier on Wednesday by a federal judge in Houston, who found that Texas has hidden information about the supplier of the drugs.
U.S. District Judge Vanessa Gilmore ordered the state to disclose, under seal, information regarding its execution drug, finding that Texas had provided information about the process by which two inmates would be executed and "masked information about the product that will kill them."
The U.S. Court of Appeals for the Fifth Circuit said the case might be different if the state were using a drug never before used or unheard of, whose efficiency was completely unknown, which was not the case.
"In sum, plaintiffs are speculating that the newly acquired pentobarbital being supplied by a new compounder may be different and may cause a risk of severe pain," the ruling said. "Speculation is not enough."
The federal judge's decision was part of a series of recent court rulings that have mandated states to release information about drugs used for lethal injection, saying that keeping the information secret violates due process protections of the U.S. Constitution.
Several states have struggled to obtain drugs for executions, while many pharmaceutical companies, mostly in Europe, have imposed sales bans because they object to having medications made for other purposes used in lethal injections.
The appeals court lifted the temporary halt to the execution of Tommy Lynn Sells on Thursday for the murder of a 13-year-old girl. It did not rule on the stay granted for a second inmate, Ramiro Hernandez, whose execution was set for April 9 for a rape and murder that took place in 1997.
SUPPLY OF EXECUTION DRUGS
Texas, which has executed more prisoners than any other state since the U.S. Supreme Court reinstated the death penalty in 1976, said last month it had obtained a new batch of the sedative pentobarbital, without disclosing its supplier.
A Texas state judge ordered the department of corrections on March 27 to disclose the name of the supplier of drugs used in executions.
Texas prison officials have so far refused, saying they want the supplier to remain secret to protect it from possible harm. That prompted lawyers for the two inmates to take the case to federal court.
In neighboring Oklahoma, attorneys for two men scheduled to be put to death this month will request a stay of execution, arguing the state is not abiding by a court ruling compelling it to provide information about lethal injection drugs.
The lawyers will raise objections to a hastily acquired batch of chemicals Oklahoma said it obtained this week for the execution of inmates Clayton Lockett and Charles Warner.
"The new protocol raises grave concerns about its safety and efficacy," said Oklahoma attorney Madeline Cohen.
An Oklahoma judge ruled last month that the state's execution procedures were unconstitutional because it did not provide to inmates the name of the drug supplier, the combination of chemicals and the dosages used in executions.
"The lawsuit involved the confidentiality statute in Oklahoma, not about the drugs themselves," Diane Clay, a spokeswoman for the Oklahoma attorney general, wrote in an email. (Additional reporting by David Bailey in Minneappolis and Heide Brandes in Oklahoma City; editing by Gunna Dickson, Bernard Orr)