The Royal Canadian Mounted Police (RCMP) has paid its members more than $1 billion of overtime since 2009, according to documents obtained by CBC News.

Recent retirees from the force say the costs confirm anecdotes that many officers are stressed, overworked and depressed.

"The rank and file — especially the patrol guys and girls — are burnt out," said Derek Snow, a recently retired RCMP member with 29 years of policing experience.

"You want to do a good job and you want to do extra," Snow said, who lives in Shediac, N.B. "But there's only so much anybody can take."

'Unlimited overtime'

Between April 2009 and June 2015, the RCMP paid $1.01 billion in overtime, according to documents obtained via access to information requests.

2009: $153,000,000

2010: $170,000,000

2011: $166,000,000

2012: $145,000,000

2013: $170,418,985

2014: $189,806,887

2015: $21,497,546 (Q1 only; April to June)

TOTAL: $1,015,723,418

"There's unlimited overtime," Snow said. "You notice a lot of the members would start working overtime. A lot of overtime.

"And then they'd get burnt out."

'You're putting members' health at risk ... and the public is at risk as well. - Terry McKee, MPPAC

Terry McKee advocates for RCMP members and acts as a spokesperson for the Mounted Police Professional Association of Canada (MPPAC).

He says the money spent on overtime should instead be used to hire more officers.

RCMP members' advocate, Terry McKee, says officers are taking more sick leave and stress leave because of inadequate staffing. (CBC News)

"You're putting members' health at risk because they're always being called to supplement for shifts that are not staffed properly," McKee said, who is based in Moncton.

"If you've got exhausted members trying to protect and serve, you've got an issue with them being alert and effective," he said.

"And the public is at risk as well."

90 per cent of members worked overtime

Internal reports obtained by CBC News reveal how overtime is managed across the force.

"Over 90 per cent of regular members received EDP [extra duty pay] compensation during the fiscal year 2014/15," said a report on RCMP work-life balance completed in May 2016.

"Relief units are not available to all small units in all divisions," the report says.

"As a result, demands on members at these units increase significantly."

The report also confirms a sentiment shared by many members — a presumed duty to work long hours when the need arises, such as when a shift is short-staffed because someone is absent.

While overtime is voluntary, "some members may feel obligated to work overtime" in order to provide support for colleagues on shift, the report says.​

'You're tired. That just goes with the job.'

Snow recounts the time when he first realized the extent of his stress.

Retired RCMP officer Derek Snow recalls his time on the force, working long hours and many days in a row. (Brett Ruskin / CBC)

"I went to a call and it was someone hiding a runaway upstairs and they lied to us," he said. "I kind of lost it a little bit, verbally, and I went back to my car and I sat there and had to shake my head."

"That's not who I am, but that's how things bubble to the surface and then you get angry," Snow said.

"You're tired. That just goes with the job."

CBC News requested an interview with the RCMP's chief human resources officer, or any member of the senior executive committee. A media relations officer declined the offer.

The RCMP also declined to provide a written statement to address or explain the overtime costs.

Contained within the documents obtained by CBC News is the RCMP's response to the work-life balance report.

"Human Resources and Corporate Management will benefit from the content of this report and are committed to providing the enhancements needed to improve operational management and oversight. We will also address the concerns outlined in this report, many of which have already been actioned," wrote Dan Dubeau, chief human resources officer.

Snow said he didn't see any attempts to reduce or manage overtime when he left the force earlier this year.

"I'm surprised it's not more," he said.