AN INQUIRY into the conviction of Phuong Ngo for the shooting murder of the NSW MP John Newman would not examine the workings of the NSW Crime Commission or the NSW police, its commissioner has said.

This is despite criticism of the Crime Commission, and the Deputy Police Commissioner, Nick Kaldas - then an detective working on the case - in the submission by a Canberra academic, Hugh Selby, which led to the inquiry.

Acting Justice David Patten, who will preside over the inquiry, also disputed that the submission on Ngo's behalf could be interpreted as criticism of the Office of the Director of Public Prosecutions by suggesting it had withheld evidence in the trial.

Mr Newman, the state member for Cabramatta, was shot at point-blank range outside his home in September 1994. Ngo, an ALP councillor on Fairfield Council, was convicted of involvement in the murder in June 2001 after one aborted trial and one hung jury. Ngo was jailed for life for ordering the killing, but two other men, accused of being the driver and the shooter, were acquitted.

Despite estimates that the inquiry could take as long as six months, Justice Patten said he wanted to limit it to the issues raised in Mr Selby's submission. It is now expected to include six weeks of public hearings and be concluded by the end of the year.

Mr Selby's submission asked for a review of Ngo's conviction on three grounds: concerns about expert evidence on mobile phone coverage; doubts about the independence of two witnesses; and the alleged failure to provide certain evidence to Ngo's defence.

Peter Bodor, QC, appearing for Mr Kaldas, the only person adversely named in the submission, said the DPP possibly had a conflict of interest in appearing for the public in the inquiry because of criticism against it.

The matter will return to court for further directions on August 6.