An Adelaide man who spent 20 years in prison only to have his murder conviction quashed in 2014 has welcomed the South Australian government’s decision to pay him $2.5 million in compensation.

The state government on Monday announced it had signed a deed agreeing to grant the ex gratia payment, which it said would help to ensure taxpayers were protected from any future litigation.

Henry Keogh, 62, said no amount of money would ever make up for the time he wrongly spent behind bars.

“You can’t put a price on 20 years,” he said.

“[But] I can move forward with my life and have some degree of financial independence and security for me and my family.”

Henry Keogh said no amount of money would ever make up for the time he spent behind bars. Photo: ABC News/Isabel Dayman

Mr Keogh was found guilty of murdering his fiancé Anna-Jane Cheney in 1995 and was sentenced to life imprisonment with a non-parole period of 25 years.

He has always maintained his innocence, and made several attempts at freedom during his jail term before his conviction was ultimately quashed in December 2014.

The Supreme Court found the original case against Mr Keogh had been tainted by the unreliable and misleading evidence given by South Australia’s then-chief forensic pathologist, Dr Colin Manock.

Mr Keogh was convicted of drowning Ms Cheney in a bath at the couple’s Magill home in Adelaide’s north-eastern suburbs.

That conviction was overturned by the Court of Criminal Appeal after it found there had been a miscarriage of justice due to flawed forensic evidence.

The court heard Dr Manock, who testified at the trial that Ms Cheney was held under the water, later changed his mind about crucial evidence.

Mr Keogh was released from prison, but in 2015 the Director of Public Prosecutions dropped his murder charge rather than holding a retrial.

“Of sorts it has [vindicated me] but I’ve gotten most of my vindication from the finding of the [Supreme Court],” Mr Keogh said.

“That’s all the vindication I need.

“Those that know me know that I’m innocent, and that’s all that’s important to me.

“For my part in this… as the principal actor… [this is the end]… but I still think there are problems with the legal system.

“Any legal system that is mature enough can admit that it got it wrong… but [it should] more importantly, take steps to prevent it from happening again.”

Mr Keogh said he was thankful to his legal team, and to Dr Bob Moles, an academic who wrote extensively about the “miscarriage of justice”.

The family of Anna-Jane Cheney has requested privacy at this time.

Henry Keogh walks from court in 2014, after 20 years in jail. Photo: ABC News

Earlier, Attorney-General Vickie Chapman said the ex gratia payment was “the most appropriate course of action”.

Ms Chapman said the government had consulted two independent lawyers over the matter.

“This is a matter which culminates a request presented to the former government just over a year ago,” she said.

“There has been a miscarriage of justice and a man has spent nearly 20 years in prison.

“This settlement has been made in full recognition of the risk to the people of South Australia… [and] weighing heavily on my mind was the prospect of further litigation.”

Ms Chapman said there was “no winner” in the case.

“There will be some in the community who take the view that this settlement is an amount that is hardly adequate for a person who has spent 20 years in prison in respect of a conviction that has been quashed,” she said.

“On the other hand, there will be other people in the community who take the view that Mr Keogh should not receive one cent.

“This settlement is not an attempt to [change their minds].

“The view of Mr Keogh’s innocence or guilt or otherwise, is academic in my assessment of this matter.”

Keogh always denied murdering his fiancee

In 1995, a jury unanimously found Mr Keogh guilty of murder and he was sentenced to life imprisonment with a non-parole period of 25 years, which was backdated to July 7, 1994.

Mr Keogh claimed he left the house on the evening of his fiancee’s death as she was about to take a bath, and when he returned home later that evening he found her lying on her side with her face under the water.

He said he removed her from the bath and attempted resuscitation.

–ABC