Daniel Scott Williams has served 12 years in jail for his role in the 1997 killing of Ulrike Conway with a dose of heroin at her Belconnen home.

Williams and his accomplice Barry Steer received only a portion of a promised $15,000 Mrs Conway's estranged husband, Australian Federal Police officer John Terence Conway and his girlfriend, Kathy Marie McFie, promised to pay them for the murder.

Sentencing Williams and Steer for the murder, Justice Ken Crispin said the killers had shown ''a pitiless determination to ensure her death''.

The two killers received reduced sentences of 27 years with a non-parole periods of 18 years, which were reduced by one-third to 12 years after they agreed to give evidence against Conway and McFie.

Williams, now 34, is eligible for parole and is seeking a judicial review of a decision of the Sentence Administration Board made in September to keep him behind bars, probably for at least another year.

In the ACT Supreme Court yesterday, Justice Hilary Penfold lifted a suppression order on Williams's name after he failed to substantiate a claim that he was in the Witness Protection Program.

The board refused Williams's parole application after a meeting on September 9, telling the prisoner its members wanted him to complete more pre-release courses.

''The board doesn't share your confidence, Mr Williams, that you're really on top of some of these underlying problems which got you into problems the first time,'' board chairman Philip Lee said at the hearing. The board is insisting that Williams undertake a violent-offender program and drug and alcohol programs.

The case will return to court in February.

Barry Steer killed himself in Goulburn Prison several years into his sentence while Conway is serving an 18-year non-parole period and McFie's 12-year minimum jail term expires next year.

For more on this story, see today's Canberra Times.