The U.S. Navy lawyer who has been defending Canadian Omar Khadr has been removed from the case, according to the deputy chief defence counsel at the Guantanamo Bay detention centre.

Michael Berrigan said Lt.-Cmdr. William Kuebler, the Pentagon-appointed lawyer for Toronto-born Khadr, was reassigned Friday following an internal probe into his conduct.

The reasons for Kuebler's dismissal have not been released, but Guantanamo's chief defence lawyer, Col. Peter Masciola, did order an internal investigation into Kuebler's conduct in February.

Kuebler has repeatedly alleged that Masciola is in a conflict of interest — that he has supported the prosecution of Khadr while also overseeing his defence.

He complained specifically about Masciola's co-operation with the review of Guantanamo cases aimed at deciding whether the cases should be tried in civilian or military courts or some combination of the two.

"I don't want to make it easier for the government to prosecute my client," he said at the time. "I want my client to be released."

In a statement released by his office, Masciola would only say that Kuebler's removal was necessary to pursue "a client-centred representation."

The Canadian government is seeking more information on Kuebler's dismissal, said Catherine Loubier, a spokeswoman for Foreign Affairs Minister Lawrence Cannon.

Kuebler waged an aggressive and public campaign on behalf of Khadr, 22, during his two years on the case. He called for the young man's return to Canada to short-circuit a military tribunal system he describes as unfair.

Khadr is accused of killing a U.S. army medic with a hand grenade during a gunfight in Afghanistan in 2002. Khadr was 15 at the time.

Like all Guantanamo prosecutions, the case is currently on hold pending a review by U.S. President Barack Obama's administration.

With files from the Associated Press