Gabe Watson, a US citizen, is accused of murdering his wife Tina whilst scuba diving in Townsville in 2003.

While Watson was convicted of manslaughter in Australia, Alabama authorities are now investigating the matter and, until now, Australian authorities had refused to assist with the investigation due to Alabama's use of capital punishment.

But in a major turnaround, Queensland authorities confirmed yesterday (6 September) that Alabama Attorney-General Troy King had undertaken not to impose capital punishment against Watson.

In response, the Queensland Government has authorised the release of further evidence in relation to the incident.

Queensland Attorney-General Cameron Dick said the undertaking was confirmed in a letter from King last week.

"I am pleased that Mr King has finally provided an undertaking in appropriate terms, stating that Alabama will not pursue the death penalty in any possible criminal action against David Gabriel Watson in relation to the death of his wife," said Dick.

Dick said that Queensland authorities had always been willing to co-operate with Alabama authorities but had to ensure that any actions taken were consistent with Australia's long-standing opposition to the death penalty.

"The government has now advised the Queensland Police Service, which holds all the relevant physical and documentary evidence, that this material should be provided to Alabama authorities as quickly as possible," said Dick.

Dick said the timeframe for the return of evidence would be a matter for the Queensland Police Service, in liaison with the State of Alabama and added that any future decision about the repatriation of Watson to the United States after the conclusion of his jail term is a matter for the Australian Government.

Watson is currently serving an 18-month sentence for manslaughter. He is due to be released in November.