Still protesting his innocence, Troy Davis is put to death

(AP)

Strapped to a gurney and at the centre of international controversy, Troy Davis died the way he has spent the past 22 years: still vigorously protesting his innocence.

Despite his being one of the most disputed cases in US legal history, Davis, right, finally lost his long-running legal battle. The 42-year-old convicted murderer was given a lethal injection half an hour after the US Supreme Court rejected his final request for a stay of execution on Wednesday.

Fifteen minutes later, at 11.08pm (4.08am yesterday GMT), he was dead. Addressing some of his last words to the family of the victim, Mark MacPhail, Davis insisted that he was not responsible for killing the off-duty police officer.

"I am innocent. The incident that happened that night was not my fault," he said. Davis then spoke to prison officials: "For those about to take my life, may God have mercy on your souls. May God bless your souls." The execution came 20 years after Davis was found guilty of the murder of Mr MacPhail. The case has been in and out of court ever since, as increasing doubts were cast on his conviction. The Pope, the former American President Jimmy Carter and a host of other public figures have said that the case represents a textbook example of the flaws in the US capital punishment system.