The public inquiry probing the arrest and deportation of Maher Arar has begun hearing arguments from groups and individuals who want to take part in the commission.

Arar is the Syrian-born Canadian who was deported back to Syria by the United States in September of 2002, even though he was carrying a Canadian passport. Arar says he was tortured while in custody.

He has long insisted that Canadian officials were aware he was going to be deported. The inquiry will determine whether files supplied by Canadian authorities may have figured in the case.

Arar himself was officially granted standing at the inquiry Thursday, meaning he'll have the right to take part in the proceedings when they begin in June.

Arar was present as his lawyer made an application for public funding so he can attend all of the hearings and pay for his two lawyers.

The commission also heard arguments from police, civil liberties groups and concerned individuals to determine who may take part in the inquiry. It will hear from almost two dozen parties requesting standing before it wraps up Friday.

Among those seeking standing at the inquiry are Ahmad Abou-Elmaati, Muayyed Nureddin and Abdullah Almalki, three other Ontario residents who were imprisoned in Syria over alleged terrorist links.

Others appearing include the Ontario Provincial Police, the British Columbia Civil Liberties Association and the Canadian Islamic Congress.

Justice Dennis O'Connor will lead the federally appointed commission. Actual testimony isn't expected to begin until June 14.

When he's done, the O'Connor will present the government with his recommendations for the creation of an independent, arm's-length review mechanism for the RCMP's activities with respect to national security.

The RCMP suspended this week its own probe of the Arar affair, pending the outcome of a federal inquiry. The Commission for Public Complaints Against the RCMP decided Monday to hold off on its investigation to avoid duplicating efforts of O'Connor's inquiry.