PHOENIX (Reuters) - A review ordered by Arizona's governor into last month's drawn-out execution of a death row inmate is underway and authorities confirmed on Friday the dosage of the controversial two-drug cocktail the prisoner received for his lethal injection.
Lawyers for convicted double murderer Joseph Wood say he gasped and struggled for breath for more than 90 minutes as he was put to death on July 23 at a state prison complex.
Arizona's assistant attorney general has said the executioners had to administer at least two full doses of the drug cocktail to the 55-year-old before he succumbed.
In a statement on Friday announcing that the probe was underway, the state's Department of Corrections said Wood was given a total of 750 mg each of the drugs Midazolam and Hydromorphone.
"I am committed to a thorough, transparent and comprehensive review process," said the department's director, Charles Ryan.
"This will be an authoritative review to ensure that fact-based conclusions are reached regarding every aspect of this procedure, including the length of time it took for the execution to be lawfully completed."
The complications in putting Wood to death, which came after two other lethal injections went awry earlier this year in Ohio and Oklahoma, intensified debate over the death penalty and prompted Arizona to suspend further executions pending the review.
An Arizona Republic reporter who witnessed the execution said that Wood gasped 660 times before falling silent.
State corrections officials have disputed any suggestion that the procedure was botched, saying Wood was fully sedated and never felt any pain.
Arizona Governor Jan Brewer, a Republican, called for the Department of Corrections to lead the review, but has said justice was done.
The department said on Friday the records showed that Ryan continually conferred as the execution was being carried out with the team administering the drugs intravenously and directed that extra drugs be administered, "ensuring the inmate remained deeply sedated throughout the process, and did not endure pain."
It said more information was being gathered, including a final report from the Pima County Medical Examiner, which will include a toxicology report.
"The timeframe for completion of the report will depend in part on the amount of time it takes to review the necessary information," the department said in its statement.
Reporting by David Schwartz; Editing by Daniel Wallis and Will Dunham