Alleging that Maher Arar's rights were violated, a New Democrat MP is calling for a public inquiry into the leak of information about the dual Canadian-Syrian citizen's deportation case.

In a letter sent to Foreign Affairs Sunday, Alexa McDonough says Arar's rights were violated by the leak of what she calls unsubstantiated information.

The letter suggests that federal officials were, in fact, responsible for the leak.

"The public reports that senior officials in your departments leaked unsubstantiated information to CTV about what Maher Arar may have said to his captors during his incarceration in Syria underscores the imperative need for a full public inquiry into what happened to Mr. Arar," the letter states.

Arar was returning to Canada from a visit to Tunisia last fall, when he was detained in New York. American authorities deported him to Syria, where he was jailed for a year.

He was released earlier this month, and has since returned to his Ottawa home.

Last week, CTV News quoted unidentified officials as saying Arar gave information about alleged Canadian al Qaeda sleeper cells while he was in Syrian jail.

In response, a spokesperson for Arar said he feels as though he has been labelled, "an al Qaeda rat."

In her letter, sent to the Foreign Affairs Minister and the Solicitor-General, McDonough said the treatment of Arar has been "immoral."

"In the absence of any judicial process, trial by leaks and hearsay violates his rights and is immoral," McDonough writes.

"If your government is to retain any shred of credibility in the eyes of all Canadians who are interested in justice, especially members of the Canadian Arab and Muslim communities who feel victims of racial profiling, it must initiate that inquiry now."