OTTAWA — Newly declassified memos show the number of Canadian landings by planes tied to the U.S. Central Intelligence Agency far exceeds previously known figures.

Internal government briefing notes obtained Wednesday also reveal senior intelligence officials from six federal agencies, including Canada's spy service, met in late November to discuss the flights.

The memos underscore the level of concern in government circles about public fears the CIA has been ferrying terrorist suspects through Canada to foreign prisons.

One note, stamped secret, says 20 planes with alleged CIA ties have made 74 flights to Canada since the terrorist attacks of Sept. 11, 2001.

The note adds the Canada Border Services Agency, which compiled the figures, and Nav Canada, the civil aviation regulatory body, "have indicated that proper administrative and operational procedures were followed in relation to those flights."

The Public Safety Department said in January a federal review of landings by the supposed CIA flights showed no evidence of "illegal activities."

The explanations do not satisfy human rights group Amnesty International, which has been pressing the government on whether any of the flights involved the transfer of prisoners to countries where they may be tortured.

"We've consistently failed to get an answer to that," said Alex Neve, the group's Canadian secretary general.

One previous media report had cited flight logs indicating that during a four-year period a total of 13 aircraft had landed in Canada on 55 occasions.

Flight data obtained by The Canadian Press shows that since mid-2005, at least seven different planes owned by reputed CIA shell corporations have landed at Canadian airports in Newfoundland and Labrador, Nunavut, Ontario and Quebec.

One recent flight, an 11-seat Beech turboprop with tail number N157A, set out for Keflavik, Iceland, on Feb. 12 from Goose Bay, N.L., where it had arrived the previous day from Montreal.

The U.S. military maintains an air station in Keflavik that serves as a refuelling point for Europe-bound aircraft.

The records released Wednesday under the Access to Information Act include an undated secret memorandum, titled Alleged CIA Aircraft in Canada, prepared by Privy Council Office officials for then-deputy prime minister and public safety czar Anne McLellan.

Considerable portions of the memos were blacked out. The deleted material was withheld under provisions of the access law that allows officials to refuse to disclose advice from officials or information related to international affairs and defence.

The Nov. 29 meeting included security officials from PCO, the Canadian Security Intelligence Service, Public Safety, Canada Border Services, Foreign Affairs and Transport Canada.

The agenda indicates they reviewed federal policy on "rendition" - the term often used to describe the transfer of suspected terrorists by the United States to countries where they may be more easily imprisoned and interrogated.

The officials also discussed the government's "public position" on the planes issue and the question of "U.S. engagement" - presumably a reference to raising the issue with American counterparts.

Gregory Jack, a PCO spokesman, and Canada Border Services spokeswoman Cara Prest declined comment Wednesday.

Public Safety Department spokesman Zuwena Robidas also refused to discuss the memos. "That's all the information that can be released."