A Toronto gun shop owner checks out the scope on a hunting rifle in this file photo. The federal Liberals want the government to release an RCMP report on the federal long-gun registry. (Kevin Frayer/Canadian Press)

The federal Opposition Liberals are demanding the Conservative government release an RCMP evaluation report of Canada's long-gun registry that concludes the program is cost effective, efficient and an important tool for law enforcement.

CBC News has learned that the report, conducted with the help of outside auditors and completed six months ago, has been in the hands of the government since February.

In a statement Thursday, the Liberals accused Prime Minister Stephen Harper's government of trying to cover up key facts about the registry ahead of a final vote in the House of Commons next month.

Liberal public safety critic Mark Holland said it is "blatantly arrogant" of Public Safety Minister Vic Toews to withhold the report "when the fate of the life-saving gun registry hangs in the balance."

On Sept. 22, MPs are slated to vote on Conservative backbencher Candice Hoeppner's private member's bill to repeal the registry.

When asked about the document by reporters on Thursday, the public safety minister insisted it has not yet been "finalized" and did not give a timeframe for when it would be released.

"As soon as that report is finalized, I will make sure that it's released," Toews said during a news conference in Winnipeg.

The Liberals said it is the second time the government has tried to withhold information on the registry from MPs ahead of a vote on Hoeppner's bill.

Disclosed government documents show that Peter Van Loan, then public safety minister, waited until two days after MPs held a second reading vote on Bill C-391 last November to table a report that said police were using the registry more than ever.

If passed, Bill C-391 would scrap the decade-old registry and destroy existing data within the system on about seven million shotguns and rifles.

The Conservatives have denounced the long-gun registry, which was introduced by the Liberal government of Jean Chrétien in 1995, as wasteful and ineffective.

'Important tool': RCMP report

CBC News has reported that one section of the report states: "The program, as a whole, is an important tool for law enforcement. It also serves to increase accountability of firearm owners for their firearms."

The report also says that the cost of the program is in the range of $1.1 million to $3.6 million per year and that the Canadian Firearms Program is operating efficiently.

“Overall the program is cost effective in reducing firearms related crime and promoting public safety through universal licensing of firearm owners and registration of firearms," CBC News quoted the report as saying.

The full report contains over 40 pages of analysis of the effectiveness of the firearms registry, in both urban and rural areas. The RCMP would only confirm that the report is still being translated and could not give a firm date for its release.

Holland sent a letter this week to House Speaker Peter Milliken to intervene, while the Liberals will continue to press for the report to be produced in committees, according to the party's release.

Police chiefs and police organizations across Canada have voiced support for the registry, saying it is a valuable tool in assisting officers in doing their job.

Some other police officers have expressed support for eliminating the registry, saying it doesn't give frontline officers any comfort when they are entering a home or pulling over a driver.