Prime Minister Stephen Harper said Thursday he has "absolutely no knowledge" of any automated calls that were allegedly aimed at suppressing the vote for Liberal and NDP candidates in the last federal election.

"I have absolutely no knowledge on anything about these calls, but obviously if there is anyone who's done anything wrong, we will expect that they will face the full consequences of the law," Harper told reporters in Iqaluit.

Opposition members are calling for a police probe into claims that a string of so-called "robocalls" placed last spring were aimed at helping the Conservatives in tight ridings.

The calls appear to have been designed to mislead voters by telling them to vote at incorrect polling stations. It's unknown who employed the company who made the automated calls.

Two NDP MPs have sent letters of complaint to both the commissioner of elections and the RCMP, urging a full investigation. And Liberal MP John McCallum says the ploy may have cost his party at least three seats.

McCallum said the calls appear to be widespread, suggesting they were the organized work of several people.

"It's not a single isolated riding, it's at least 18 that I'm aware of across the country, and I can't imagine how one single operative woke up one morning to target all those 18," he told CTV's Power Play.

"I don't have a (smoking) gun for the prime minister, but I think it must have been arranged at some central level to some degree, and hopefully this investigation will give us some answers."

New Democrat MP Pat Martin said he was aware of about eight ridings where the calls took place, and his party ended up losing two of them.

"It's hard to overstate how serious this is," he said. "You are denying somebody their fundamental right to cast their ballot in a free and fair election by deliberately mischievous means."

Newspaper reports said that Elections Canada had traced the phone calls to Racknine Inc., a small Edmonton voice-broadcast company that worked for the Conservative party's national campaign and at least nine other Conservative candidates, including the prime minister.

Company officials said they had no idea who made the calls and have handed their records to authorities. They also said that outgoing messages are not monitored.

In an email to CTV News, Racknine president and CEO Matt Meier said he was "shocked and distressed to learn that some party had used our services to try and disrupt voting."

There is no evidence that Harper's campaign or any of the other candidates were involved in the calls, the reports said.

A spokesperson for the Conservative party strongly denied any involvement in the calls.

"The Conservative Party of Canada ran a clean and ethical campaign and would never tolerate such activity," Jenni Byrne, the party's national campaign manager, said in a statement. "The party was not involved with these calls and if anyone on a local campaign was involved they will not play a role in a future campaign.

"Allegations of voter suppression are extremely serious," Byrne continued. "If anything improper occurred, those responsible should be prosecuted to the full extent of the law.

Elections Canada said it does not comment on, nor confirm, ongoing investigations.

It launched the probe after it was besieged with complaints about a series of bizarre election-day phone calls made to residents in Guelph, Ont.

Voters there received recorded calls from people pretending to be from Elections Canada, informing them that their polling stations had been moved. The calls resulted in chaos at some polling stations. Other voters stayed home.