A Canadian naval intelligence officer pleaded guilty today to handing over secrets to an unidentified foreign country, the Canadian government said.

Sub-Lieutenant Jeffrey Paul Delisle made the plea through his lawyer during a preliminary court appearance in Halifax, Nova Scotia.

The judge in the case has imposed a publication ban on much of the proceeding, although some Canadian media outlets began publishing extensive details of Delisle's activities, which had been outlined in previous secret court sessions.

Delisle, 41, was charged with breach of trust and two counts of passing information to "a foreign entity". Canadian authorities would not comment on media reports that the foreign country in question was Russia.

Christian Leuprecht, an analyst at Queen's University and the Royal Military College, in Kingston, Ontario, said it was in the best interest of the Canadian government not to have become involved in a long court battle, which could have released sensitive information to the public.

"The Crown would prefer to keep all these details under wraps in order not to make public the extent of the damage done to Canada's national security and to safeguard the counter-espionage methods Canada deploys," he said.

Delisle's sentencing hearing will be held on Jan. 10 and 11 next year. He was arrested in January.

The Canadian Broadcasting Corp cited military officials as saying Delisle worked for a unit that tracked vessels entering and exiting Canadian waters. It said the unit had access to secret data from NATO countries.

Defence Minister Peter MacKay said in January that Canada still enjoyed the confidence of its allies despite the arrest. Canada has an intelligence-sharing arrangement with the United States, Britain, Australia and New Zealand.

Delisle is the first person charged under a new secrecy law enacted after the Sept. 11, 2001 attacks.