The RCMP has spent more than $800 million in overtime costs in the last five years.
Figures obtained by CBC News Network's Power & Politics through Access to Information show the overtime tab was a little more than $126 million in the 2007-2008 fiscal year; and that climbed to about $160 million last year. The total does not include extra duty pay for standby or operational readiness.
Some of the cost spikes are due to special events like the 2010 Olympics in Vancouver, the North America Leaders' Summit in Montebello and the G8 and G20 summits in Huntsville, Ont., and Toronto.
The RCMP says the increase mirrors the general growth in salary costs, and that overtime as a percentage of total salary costs has remained relatively static at about six per cent.
"Policing is a 24/7 line of work," said RCMP spokesman Sgt. Greg Cox. "Therefore, overtime may be incurred as a result of operational requirements to ensure the continued safety and security of the communities we police."
A number of factors can come into play concerning overtime requirements, including remote locations, shift changes, travel time and special events, Cox said.
Security operations at the Vancouver-Whistler Olympic Games led to a spike in costs in 2010, when overtime costs reached nearly $190 million.
Cox said about two-thirds of the overtime costs relate to contract policing services to provinces, territories, municipalities and First Nations communities.
There are about 19,200 regular members and another 3,760 civilians in the RCMP.
Retired RCMP officer Rob Creasser, who has been pushing for a union within the ranks, said the overtime tab runs high due to understaffing.
"It's because detachments across Canada are not properly staffed in the first place," he said. "There are very few detachments nation-wide that are running with the proper complement of members they are supposed to have. Couple that with people burning out because of work overload and you get the picture. Not a great work environment."
But Julie Carmichael, spokeswoman for Public Safety Minister Vic Toews, said the Conservative government has added and filled 1,000 new RCMP positions, and called it "natural" that the Mounties would incur substantial overtime hours for significant international events such as the Olympics and summits.
"When the Liberals were in power, they shamefully closed the RCMP depot and reduced recruitment to zero," she said.