Botched executions using lethal injections have been stirring the debate in the US on a possible stop to the same. REUTERS

The US Supreme Court on Tuesday allowed an Arizona execution to go forward after a federal appeal court had put it on hold over secrecy surrounding lethal injection drugs in the country.

The state plans to execute death row inmate Joseph Rudolph Wood on Wednesday.

Wood, 55 who was convicted of murder of his estranged girlfriend and her father, used his First Amendment right to know details about the state's lethal injection method, the qualifications of the executioner and the drugs manufacturers.

Upheld by the 9th US Circuit Court of Appeals, the First Amendment did not hold water with the Supreme Court which ruled against the defence lawyers each time the transparency issue came up.

The appeals court had earlier stayed the execution of Wood because the state refused to give the inmate details about the drugs it planned to use to execute him.

Wood's public defender made use of the botched June 29 execution in Oklahoma, in which Lockett, the inmate, writhed in apparent agony for 43 minutes before he died.

Wood was among five other death-row inmates who sued over concerns that executions would be carried out with the same drug used in the botched Oklahoma execution, midazolam. They claimed that midazolam is unsuitable for use in executions and that the execution teams lack expertise, backup plans and supplies.

Prison officials have said they believe a vein collapsed after the IV was inserted into Lockett's groin, but medical reports found evidence of "failed catheter access." The prison director said an intravenous line blew after Lockett was given midazolam, a sedative, and while two other drugs, the paralytic vecuronium bromide and the heart-stopper potassium chloride, were flowing into his body.

Many pharmaceutical companies have been refusing to sell products for capital punishment, making it tough for prison authorities to source drugs for the lethal injection combo: pentobarbital and vecuronium bromide. They have been forced to turn to less-regulated pharmacies for their deadly cocktails.

States are trying to keep the supply lines open by giving their drug connections anonymity, resulting in secrecy.

Two other executions using new cocktails have drawn scrutiny because of complications. When Michael Lee Wilson, 38, was put to death in January in Oklahoma for the murder of a store clerk, he reportedly blurted out, "My whole body is burning," after the pentobarbital was injected.

In Ohio, Dennis McGuire, 53, took 25 minutes to die and was seen gasping for breath in January when given an untested cocktail that included midazolam.

Lawmakers in some death-penalty states are pushing for non-medical forms of execution, such as firing squad or electric chair but public support is missing.