Police say Const. Daniel Daudet was arrested in a rural municipality southeast of Winnipeg.
He faces possession of cocaine, possession of a prohibited firearm obtained by crime and other charges.
RCMP say Daudet, who is 42, has been a Mountie for 13 years.
He has been released from custody and is to appear in Steinbach provincial court on Feb. 19.
Police say he has been suspended with pay.