Two men found guilty of ambushing and killing a drug dealer in the dead of night on a bridge near the Victoria-South Australia border have told police where they dumped his body, a court has heard.

The body, believed to be that of Gordon Hamm, 34, was found on Thursday at Dergholm, 130 kilometres north of Nelson.

Crown prosecutor Michele Williams, SC, told the Supreme Court on Friday that there had been an unusual development in the case after lawyers for Mark Moreland and Christopher Tippins contacted the Office of Public Prosecutions on January 16 saying the two men had information as to where Mr Hamm's body could be found.

Moreland, Tippins and Tai Thorp had been found not guilty of murder but guilty of manslaughter by a Supreme Court jury last month despite Mr Hamm's body having never been found.

The Crown case was that the three men had taken part in a joint criminal enterprise out of greed to kill Mr Hamm on July 17, 2013.

Ms Williams told the court on Friday that police went to see Moreland and Tippins in prison who told them where they could find Mr Hamm's body.

Moreland led police to the remote location on Thursday where the body was found.

Ms Williams said the body had yet to formally identified but police were "pretty confident" it was him.

Justice Michael Croucher, who had been due to hear a pre-sentence hearing for the three men on February 13, agreed to postpone the hearing until March 26 to give the Crown more time to gather information about the case, including the results of an autopsy report on the body.

Mr Hamm was being driven back to Mount Gambier from Portland by Samantha Porter when she drove on to the Nelson bridge over the Glenelg River just before 4am.

Mr Hamm was believed to have been in Portland to buy drugs after earlier winning between $5000 to $6000 on the pokies.

A four-wheel drive being driven by Moreland drove towards Ms Porter on the bridge with his lights on. As Ms Porter attempted to reverse, she hit a car behind her being driven by Thorp and was jammed in.

Moreland and Tippins, who had been in Thorp's car, then dragged Mr Hamm out of Ms Porter's car before a shot was fired.

Mr Hamm was repeatedly bashed with the rifle butt and was on his hands and knees when Tippins told Ms Roberts to "get out of here". Ms Roberts claimed Mr Hamm was "squealing like a pig" at the time.