The Queensland DPP originally charged Watson with his wife's murder but, under circumstances which are less than clear, the charge was later downgraded to manslaughter.

Watson, who is a US citizen, pleaded guilty to the charge and the case was never tried before a jury, despite a recommendation from the Coroner that the case go to trial.

Tina Watson died of asphyxiation during a scuba dive in Townsville in 2003, shortly after the couple's wedding.

The official finding that Gabe Watson merely failed to assist her when she was in distress was questioned by many people who believe he should be tried for murder.

Despite Watson's Australian conviction, US authorities conducted their own investigations, which were initially hampered by the Queensland Attorney-General's refusal to hand over evidence until US authorities pledged not to sentence Watson to death should he be found guilty of murder.

This undertaking was given in September and the evidence was handed over, enabling investigations to be completed.

A US grand jury last week made a decision as to whether Watson will be indicted for murder, but the decision can only be revealed if and when Watson is arrested.