Australian and Canadian officials are reportedly in discussions about a spy who allegedly passed information from Australia and the US to a foreign power.

Sub-lieutenant Jeffrey Delisle, a 41-year-old Canadian intelligence officer who worked at a naval intelligence hub in Halifax, was arrested earlier this year.

Security officials say he passed secrets to a foreign power for nearly five years.

The government in Ottawa is not naming the foreign power, but it is believed to be Russia.

Several Russian diplomats were asked to leave Canada shortly after Delisle was arrested in January.

Prime minister Stephen Harper would not comment on Australian media reports that Canadian security officials briefed Australia's high commissioner about the case.

Security experts say the breach has damaged Canada's security relations with some of its key allies.

It is also believed that Delisle's actions have been the subject of high-level meetings between the Australian and Canadian governments, and were on the agenda at a secret international conference in New Zealand.