Lawyers and supporters of Jackie Elliott, the British-born man convicted of a murder in Texas 17 years ago, reacted furiously yesterday to his execution, saying the US legal system had refused even to look at compelling evidence pointing to his innocence or to allow more time for DNA testing.

Elliott, who was 42, was put to death by lethal injection on Tuesday night after a flurry of last-minute petitions were turned down by the Texan and the federal courts.

The state's reputation for cowboy justice – it has executed 296 people, more than any other state, since the death penalty was reinstated by the US Supreme Court in 1976 – was highlighted when the prosecution produced 51 pages of potentially exculpatory evidence hours before the execution but no judge thought the documents were worth examining before going ahead.

The court also chose to disregard petitions from all 12 original trial jurors, who said they would not have opted for the death sentence had they seen all the evidence and that they favoured a commutation.

Richard Bourke, an Australian lawyer who worked on Elliott's case for Reprieve, a British anti-death penalty charity, said: "The appeals process has done nothing to put to rest the serious doubts about Jackie's guilt. All it does is heighten them.

"The prosecution held on to paperwork that they should have handed over 16 years ago. Their behaviour makes a mockery of their responsibilities to seek justice for all," he said.

In 2001, the last-minute unearthing of prosecution documents was enough to delay the execution of Timothy McVeigh, the Oklahoma City bomber, by a month on the ground that defence lawyers had a legal right to examine all documents of potential benefit to their client. Texas does not oblige prosecutors to hand over any material unless the defence specifically asks.

Elliott's case raised many concerns about the fairness and safety of capital convictions. His court-appointed lawyers had no experience of a criminal trial, much less a murder case. The chief prosecution witnesses were fellow suspects offered lenient terms for testifying. And a forensic "expert witness", who testified about blood patterns on Elliott's clothing, turned out to have a track record of flawed assessments.

Elliott was one of gang of young men present at the rape and murder of Joyce Munguia, an 18-year-old single mother, in Austin in June 1986. One of the others was the owner of the motorbike chain used to kill the victim while a third was later heard bragging about his part in the killing. Elliott's lawyers believe he was set up to take the fall because, as a mixed white-Hispanic man, he was considered the outsider of the group.

When Reprieve petitioned the Texas district court with the new evidence they had found in just six weeks of work, the first judge who heard them, Jan Wisser, told the Texas Board of Pardons and Paroles he had "not had contact with any defendant more deserving of the ultimate penalty". Later, after reading the files, he told the district attorney in an e-mail that he "felt that there might be merit" on the DNA issue.

Judge Wisserrecused himself and was replaced by Judge Chuck Campbell, who admitted he had not read the files and showed no interest in doing so. Partly because of pressure from the British government, prosecutors in Austin came close to cutting a deal with Elliott's lawyers and waiving the death penalty on review of the new evidence but, Mr Bourke said, they were simultaneously considering a parole request in the case of the notorious Austin "yoghurt shop killings" – which they granted. "It was a bad week to ask for clemency twice," he said.

* The International Court of Justice in The Hague ordered the US yesterday to stay executions of three Mexicans – two in Texas. Mexico says more than 50 of its nationals on Death Row should get retrials because the authorities failed to tell them of their rights to consular help after their arrests.