OTTAWA (CP) � A top Nazi hunter hired to help Canada pursue suspected war criminals is under investigation for perjury by the Justice Department in the United States.

Neal Sher, a Washington lawyer, told the Commons justice committee Wednesday that he is being investigated by the Office of Professional Responsibility, a unit of the U.S. Justice Department that handles complaints about attorneys.

The allegations date back to 1990 when Sher was director of the U.S. Office of Special Investigations, which is responsible for hunting Nazi war criminals in the United States.

The office has been accused of withholding evidence that might have been helpful to the case of Andrija Artukovic, a California resident who was extradited to Yugoslavia for war crimes during the Second World War.  Sher said he has been assured that the allegations against him are groundless, but no official verdict has been rendered.

John Sims, assistant deputy attorney general, said he was not aware of the investigation when he hired Sher as a consultant to help the federal government track down war criminals.

Sims said he found out about it a couple of days ago from a colleague in his department.  He said he has not mentioned the fact to Solicitor General Andy Scott.

Sher was summoned to appear before the committee at the request of members who say they have been hearing concerns about his role and background.

Conservative MP Peter MacKay said Sher should be dismissed from his job advising the federal Justice Department.

"It's a little shocking to think that somebody that is being relied on heavily by the Canadian government is himself under investigation for potential � and I key on the word potential � frauds perpetrated on the court," said McKay, a former Crown attorney.

"It comes as a bit of a disappointment that the Canadian government didn't do their research first and have that knowledge themselves.  I think he should be paid for his advice and sent packing."

Reform MP Jack Ramsay said he was surprised at Sher's statement that allegations against him are unfounded.

"What I found interesting is that investigation is not over and yet he knows the results of it at least in part."

Sims said Sher is working for the Justice Department two or three days a month and gets paid $200 US per hour.  He said Sher's advice has been helpful.

Much of the Sher's testimony before the committee dealt with his role in the extradition from the United States of John Demjanjuk, who was accused of being a Nazi death camp guard known as Ivan the Terrible.

Demjanjuk was eventually acquitted of war-crimes charges in Israel and returned to Ohio.

Sher conceded there were errors in the handling of the case.  The Canadian Jewish Conference issued a statement Wednesday strongly endorsing Sher's engagement as a consultant.

"Examining the totality of Mr. Sher's career at the Office of Special Investigations and after reveals a record of outstanding success and energy in bringing alleged Nazi war criminals to the bar of justice," the statement said.