An internal RCMP review says the Conservative government's choice of Ontario cottage country as the 2010 G8 Summit venue offered would-be snipers "ideal conditions" to assassinate a world leader.

It says the hilly, wooded terrain around Huntsville, Ont., featured not only excellent vantage points for gunmen, but covered approaches for intruders, and problematic land and water routes leading in and out of the area.

The 353-page review was released to The Canadian Press in response to an Access to Information request.

It also says the decision to host the G20 Summit in Toronto immediately afterwards "added a significant planning challenge" that prompted a "complete re-examination of the G8 Summit security."

Security for the G8 and G20 events in late June 2010 involved over 20,000 personnel from across the country and a budget of $930 million — the biggest domestic security operation in Canadian history.

Disclosure of the RCMP's security concerns about the Muskoka G8 venue follows an auditor general's report that said the federal government "did not clearly or transparently" explain how $50 million was going to be spent in the region, home to senior cabinet minister Tony Clement.