The security plan for protecting the G20 summit venue in June 2010 involved bringing police officers from across the country to Toronto. (Lefteris Pitarakis/Associated Press)

The bill for security at last summer's G8 and G20 summits could have been much lower if the government had used more military personnel instead of police officers, Canada's parliamentary budget officer says.

Kevin Page's comments on Monday came in response to a CBC/Radio-Canada report that revealed the RCMP contracted hundreds of police officers from across the country to travel to Ontario for the two summits, and paid millions in premiums to them for working on days off or during vacations.

Page also cited the decision to host the dual summits at separate venues in Toronto and the Muskoka region as the main reason why the final price tag is expected to exceed more than $1 billion.

"Could we have saved money? Yes. If the decision was made that we could have had one venue as opposed to two, we could have reduced those costs quite significantly," Page said Monday.

"If we were comfortable having more of a military presence, as opposed to an RCMP presence, we might have been able to save costs further."

CBC/Radio-Canada obtained copies of RCMP contracts totalling $7 million for the hiring of 657 officers from 17 different local forces from coast to coast. The invoices detail how over the course of a week or two in June 2010, more than half of all the work performed by those officers was paid for at premium rates of 1½ or two times an officer's usual wages.

The Conservative government has repeatedly defended the security costs, saying Canada had a responsibility to protect visiting world leaders, as well as thousands of delegates and media members, during the "unprecedented" back-to-back hosting of the events.

"We took this responsibility seriously and we are proud of the men and women who ensured their protection from thugs who intended to disrupt the summits," Public Safety Minister Vic Toews's office said in a statement Monday.

The final costs are still being calculated but are expected to come in under budget, Toews's office added.

"These costs were made available to the media in 2010. Disclosing the full to-date details of the costs of these summits is further proof of our government’s commitment to transparency and accountability," the minister's office said.

"In fact, this level of transparency in disclosing all costs down to the penny involved in hosting summits is unprecedented, in Canada and internationally."

But Page said he expects even more questions about spending when the auditor general's final report on G8/G20 summit spending is released.

That report is expected to be tabled in Parliament on June 9 and will focus not just on the estimated $650 million spent on police and security, but also the tens of millions of dollars spent on infrastructure projects across the Parry Sound/Muskoka region — the site originally picked to host both summits.

"I think there will be a lot of interest in that report," Page said.

With files from Dave Seglins