HALIFAX - Alleged terrorist Adil Charkaoui was halfway through a flight to Montreal from Fredericton this month when the plane turned back to New Brunswick and he was ordered off the flight, he said Thursday.

Charkaoui, who is on a national speaking tour, said he was the only passenger told to leave the aircraft.

"Just me," he said in an interview from British Columbia.

"After flying 45 minutes, the plane returned to Fredericton and they asked me to go outside the plane. I asked why and the airline refused to give me any reason."

Charkaoui declined to name the airline.

However, the website for the Fredericton airport identifies Air Canada as the only airline providing domestic services out of the city.

Isabelle Arthur, an Air Canada spokeswoman, confirmed by email that a June 3 flight to Montreal did turn back to Fredericton.

She said the flight "had been cleared by the American authorities prior to takeoff (but) was subsequently refused entry into U.S. airspace and therefore had to return to Fredericton."

Arthur said Air Canada did not have further information on the incident and "questions should be directed to American authorities."

Charkaoui is a landed immigrant from Morocco who was arrested in Montreal in 2003 under security-certificate legislation.

The Canadian Security Intelligence Service contends the school teacher and part-time graduate student is an al-Qaida sympathizer who should be sent back to his native Morocco.

Charkaoui denies any links to the terrorist group.

Last June, the Supreme Court of Canada criticized CSIS for destroying the original evidence behind its allegation that the Montreal father of three is a terrorist.

Prime Minister Stephen Harper was asked Thursday about the incident during a news conference in Halifax at Pier 21, a former entry point to Canada for millions of immigrants.

Harper replied that he didn't know much about it but said Charkaoui is on a no-fly list in the United States and Canada has a security obligation to enforce it.

Charkaoui said he was actually watching the news conference when his name came up.

"I found it sadly ironic that on the day he was in Halifax talking about immigrants in Canada that me, son of two Canadians and the father of three Canadians, I could not get the same treatment and my rights being respected as any Canadian in this country," he said.

Charkaoui said he had clearance from Transport Canada and the Canada Border Services Agency for the flight, which would have travelled in part in U.S. airspace.

He said he flew to Fredericton from Montreal without incident but was told by the airline that someone called U.S. officials about his presence on the return flight.

"We have an order from the Federal Court that allows me to travel and somebody called and put me again in trouble," Charkaoui said. "So those people didn't learn from the true decision of the Supreme Court of Canada."

"When last year the Supreme Court told CSIS that you have to ... respect the Canadian charter. I don't think they learned from this decision."

In February, a Federal Court judge eased some of the conditions imposed on Charkaoui.

The judge said some of the restrictions had become disproportionate given the number of years that had passed since he first faced terrorist allegations.

The ruling means Charkaoui is able to go out unsupervised and is allowed access to the Internet on his home computer, although he is closely monitored.

Charkaoui called for an inquiry into the June 3 incident.

"I'm asking he Canadian government to have a full inquiry to know who called the Americans. ... We are going to bring the issue in front of the federal courts. We need to have the facts."