Niels Ortved, who represents Dr. Charles Smith, surprised the inquiry looking into his client's actions by bluntly taking issue with James Lockyer, the lawyer for nine people who faced criminal prosecution in Mr. Smith's discredited cases.

Mr. Lockyer, a founder of the Association in Defence of the Wrongfully Convicted, sat on the provincial committee that set up the review of the pathologist's work by international experts.

He had close personal contact with the experts and access to information in all the cases they looked at, Mr. Ortved said.

The lawyer's questions of witnesses at the inquiry Thursday underscore the appearance that he is biased against Mr. Smith, and raise questions about his whole role in the controversy, Mr. Ortved said.

In one question, Mr. Lockyer suggested the review found the pathologist had an error rate of 57%, though the assessment only considered a small fraction of about 1,000 autopsies he performed between 1991 and 2001.

"That is a complete and irresponsible distortion and raises the question . . . of whether Mr. Lockyer's participation in the review process tainted it," Mr. Ortved told the inquiry, striking the first note of conflict at the generally sedate hearings.

"Mr. Lockyer has now put himself in the position of becoming a potential witness concerning the review process."

Mr. Ortved said he may petition that the lawyer be barred from the inquiry, where he speaks for nine people convicted of criminal offences due in part to the discredited autopsies.

Mr. Lockyer has built a national reputation as a crusader for people caught in miscarriages of justice, from Guy Paul Morin to Steven Truscott.

"I'm a little taken by surprise -- a lot taken by surprise," he said, but indicted he would not comment on the bias allegations unless Mr. Ortved formally asks that he be removed from the inquiry.

The international review examined 45 of Smith's cases between 1991 and 2001, and found serious errors in 20 where there were suspicions of criminal behaviour. A handful of the parents and others charged in those deaths have had their cases dropped or guilty verdicts overturned, but others still have convictions on the record.

Mr. Ortved also accused Mr. Lockyer of overstepping the bounds of the inquiry by asking witnesses about specific cases involving his clients, and suggesting they should be declared miscarriages of justice.

The commission, appointed by the Ontario government, is supposed to look generally at the system of pediatric forensic pathology in Ontario, and not report on specific cases.

"That series of questions (by Mr. Lockyer) is contemptuous of the strictures imposed on this commission," Mr. Ortved charged. "Everyone else has played by the rules . . . There shouldn't be one set of rules for all of us, and another set of rules for Mr. Lockyer."

Mr. Lockyer, however, said he raised the case of one of his clients to highlight the possible injustices that stemmed from Smith's flawed autopsies or testimony, and the need to fix those wrongs. That corresponds with the inquiry's mandate to rebuild faith in the child-death autopsy system, he argued.

Justice Stephen Goudge, who heads the inquiry, said he was not concerned that any of the questioning had strayed beyond the inquiry's mandate.