OTTAWA — Russian Ambassador Georgiy Mamedov says Moscow has a deal with the Canadian government to "keep quiet" about his country's involvement in the case of a naval intelligence officer accused of spying.

Sub-Lt. Jeffrey Delisle is in custody on charges of passing secret military information to a foreign entity. CTV has reported Delisle passed on secrets to the Russians and Canada retaliated by expelling several Russian diplomats.

"I have a deal with your people to keep quiet," Mamedov told CTV during a brief conversation at a Russian embassy event. "But after this seal of silence is lifted, I will tell you and you will be very red-faced."

Asked directly if Delisle was spying for the Russians, Mamedov said: "I don't know because I am not the guy who controls Humint (human intelligence). But I can tell you what you said about some people in my embassy are dead wrong."

CTV reported that six Russian diplomats have left Canada since Delisle was arrested in mid-January, including two military attachés. Sources say some of those diplomats were asked to leave as a result of the spy scandal.

Mamedov declined to say which of the six Russians were asked to leave by the Canadian government.

"I am not at liberty to discuss because I don't want to influence your judicial process," he said.

Mamedov also said it is possible Russia's role in the Delisle spying case will never be known.

"It will depend on the entire interests of our bilateral relations because you are interested in good relations with the Russians . . . so I am working for you as much as for my taxpayers."

The ambassador, who has been in Canada since 2004, would not say if Moscow asked any Canadian diplomats to leave. Insiders say Canada is downplaying Russia's involvement in the spy affair to avoid tit-for-tat expulsions of Canadian diplomats in Moscow.

According to court documents, investigators allege that between July 6, 2007 and Jan. 13, 2011, Delisle committed a breach of trust and communicated to "a foreign entity information that the Government of Canada is taking measures to safeguard."

The Russians allegedly recruited Delisle while he was working as a naval intelligence officer in Ottawa. He ended up in Halifax where sources say he handled highly sensitive information.

Exactly what secrets Delisle allegedly passed on to the Russsians is not known.

Military attaché Colonel Sergey Zhukov, deputy military attaché Lt.-Col Dimitry Fedeorchatenko; diplomats Konstantin Kolpakov and Dimitry Gerasimov; and technical staffers Mikhail Nikiforov and Tatiana Steklova were removed from the Foreign Affairs list of Russian diplomats over the past month.