Elections Canada is confirming for the first time that it's investigating automated robocalls that may have redirected voters to the wrong polling stations during last spring's federal election.

The agency had previously said only that it makes a practice of not confirming investigations. However, the RCMP confirmed it was providing support to the agency. The agency also said in a post-election report that it was looking into crank calls.

"The Office of the Commissioner of Canada Elections confirms that it is investigating complaints received regarding robocalls placed at the 41st general election in 2011," John Enright, spokesman for Elections Canada, said in a statement.

The agency has received more than 31,000 "contacts," Enright said, meaning emails, phone calls or letters.

"Elections Canada has received a high volume of complaints in recent days as a result of MPs and political parties calling on the public to send information to the agency. … Elections Canada is reviewing these and will take action as appropriate."

Interim Liberal Leader Bob Rae says the complaints show significant dissatisfaction.

"This is a literally unprecedented number of complaints," he said Friday in Ottawa.

"Unless the prime minister and his associates want to say there are 31,000 Canadians and more participating in a smear campaign, he’s going to have a hard time dismissing these complaints."

Questions about Thunder Bay call centre

Asked about a CBC News report that Conservative officials are reviewing election-era recordings from a Thunder Bay, Ont., call centre, Rae said if the report is true then it's inappropriate.

"This is evidence," he said. "You can't be seen to be looking at evidence before somebody else looks at evidence."

Dean Del Mastro, parliamentary secretary to Prime Minister Stephen Harper, denied the report in the House of Commons.

"Of course the Conservative Party of Canada is doing no such thing," he said during question period. "We have made certain, as we’ve said in this House many times, everything that the Conservative Party has done is available to Elections Canada. We have nothing to apologize for, Mr. Speaker."

Speaking to reporters, Del Mastro said the Conservatives have "all of the evidence on our side to indicate that we have absolutely no involvement in any of the allegations the opposition has brought forward."

Despite an embarrassing mix-up Thursday in which the Conservatives drew a link between the Liberals and a U.S.-based company, but confused Canadian and American companies with the same name, Del Mastro continued to argue the opposition party harassed its own supporters.

The Liberals had said some of the harassing calls reported to their campaigns had U.S. area codes.

Del Mastro had said the U.S. area code proved the calls came from the Liberals because they were the only party to use a U.S.-based call centre. In fact, the Liberals used the Canadian company with a similar name.

But he persevered with the argument Friday.

"It seems very clear to us that the Liberal party has, in fact, spent millions of dollars on a nationally orchestrated, documented, well-planned, phoning campaign where they contacted folks they believed were Liberal supporters right across the country," he said Friday.

In reference to the number of complaints being investigated, NDP MP Pat Martin said it's just not plausible to have that many calls made in error.

"To try and change the channel by implying the Liberals did it to themselves, this nationwide conspiracy to sabotage their own election, and then to say, oh well, maybe there was a few mistakes made. You know, maybe the robo fairy actually spilled over and called a few people they shouldn’t have called," he said.

Enright wouldn't say whether the investigation is expanding beyond Guelph, Ont., where court documents show Elections Canada started looking into robocalls on May 12, 2011, 10 days after the election.

The agency said in its post-election report that it received 1,003 complaints, including complaints about crank phone calls, unsolicited phone calls and automated phone messages.

There were 1,352 complaints from the 2008 election and 329 from the 2006 election.

The agency's commissioner will report to Parliament "in due course," he said.