ESQUIMALT, B.C. -- Two members of a Canadian warship's crew have been charged with drug offences in Japan, the navy says.

The charges follow a port visit to Tokyo by HMCS Winnipeg, a Halifax-class frigate with a crew of about 250 personnel.

The navy said in a news release that police detained two military members and a civilian employee on Monday for the alleged use of a controlled substance.

Police released one of the military members but have charged the other two with use of a controlled substance, the navy said.

Rear-Admiral Gilles Couturier, commander of Maritime Forces Pacific, called the allegations troubling.

"While it is too early to speak to the specifics of any actions or investigations at this point, I can state definitively that our response will be based on facts and will serve to remind and reassure all who serve in the (Royal Canadian Navy) that unacceptable behaviour, whatever its nature, has no place within our ranks," he said in a statement.

The Canadian Armed Forces has a zero-tolerance policy for the possession and use of illicit drugs.

The navy said it will work with Canadian consular officials and Japanese authorities and will support the individuals who are being held in custody, and their families at home.

HMCS Winnipeg deployed from Esquimalt, B.C., on June 15, 2015.

It participated in Operation Caribbe, a multinational campaign against drug trafficking in the Caribbean and the eastern Pacific Ocean, before joining NATO forces in the Mediterranean Sea as part of Operation Reassurance.

HMCS Winnipeg was replaced in the latter operation by HMCS Fredericton, which deployed from Halifax on Jan. 5.