Evidence suggesting the man suspected of the Bowraville murders was seen standing over the body of an unconscious Aboriginal teenager is "irrelevant" and witness accounts may be "contaminated", a Sydney court has heard.
Senior public defender Mark Ierace is representing the man suspected of killing three Aboriginal children, Evelyn Greenup, 4, Clinton Speedy-Duroux, 16, and Colleen Walker-Craig, 16, over five months between 1990 and 1991 in northern NSW.
The man, who cannot be identified, was acquitted of Clinton's murder in 1994 and of Evelyn's murder in 2006.
The Court of Criminal Appeal is presiding over a landmark hearing to decide whether there is fresh and compelling evidence to quash the man's previous acquittals and order a re-trial.
The court heard witness statements from two delivery drivers who reported seeing a man standing over the body of an unconscious Aboriginal teenager on February 1, 1991 — the same morning that Clinton disappeared.
But Mr Ierace argued those accounts were unreliable and inconsistent, and relate to an incident which occurred a week earlier.
"The evidence is inherently inadmissible because it's not related to a fact in issue," he told the court.
"When you look at the evidence it relates to an incident on the 25th of January — it's entirely irrelevant.
"It doesn't have any role to play in the interests of justice."
Mr Ierace also argued that serious inconsistencies between the two delivery drivers' original statements, and statements they gave to homicide detectives when the case was re-opened in 1997, raised "the concern of conscious or unconscious contamination" of their individual accounts.
The court previously heard lawyers for the Attorney-General would rely, in part, on the evidence of four police informants.
Wendy Abraham QC argued the key suspect confessed details of the alleged murders to the four informants while he was on remand in prison.
But Mr Ierace cast doubt on their evidence, telling the court that one of them, known only as Mr I, was a "fantasist" who was prone to "big noting himself".
Mr Ierace also questioned the reliability of another informant, known only as Mr K, who was a registered informant and provided information to police in exchange for money.
The hearing is the first test of the state's double jeopardy laws and is unprecedented in NSW and in the United Kingdom where similar laws exist.
The hearing will run until early next week, with a decision expected at a later date.
