CBC News has learned that more than a dozen Conservative MPs employed U.S.-based political telemarketing firms during the last federal election campaign, contrary to Stephen Harper’s statement in Parliament this week.

The prime minister and his parliamentary secretary, Peterborough MP Dean Del Mastro, claimed in the Commons that the Liberals were the only party that used American calling firms.

"We’ve done some checking," the PM said, and "we’ve only found that it was the Liberal Party that did source its phone calls from the United States."

But documents show 14 Conservative campaigns enlisted the telephone services of an Ohio company called Front Porch Strategies.

During the election, the company made thousands of calls into each of those Canadian ridings from its headquarters in Columbus.

In fact, Del Mastro’s own campaign used the American firm twice during his successful bid for re-election last year.

The campaign of Conservative MP Dean Del Mastro was one of 14 Tory campaigns that used an Ohio-based political telemarketing firm during the last federal election campaign, documents show. (Adrian Wyld/Canadian Press)

Del Mastro was already left red-faced earlier this week after he accused the Liberals of using an American telemarketing firm which, in fact, is a Canadian company.

A source connected to Front Porch tells CBC News that all the calls from Ohio to Del Mastro’s riding during the election were programmed to show the telephone number of his local campaign headquarters, masking the fact the phoning was being done from Ohio.

Front Porch’s calls to 13 other ridings on behalf of Conservative candidates operated in the same way, the source said.

There is nothing illegal about Canadian political campaigns using the services of American telemarketing firms, and it is unclear why the Conservatives tried to tarnish the Liberals with the issue.

Calls to executives at Front Porch in Ohio were not returned.

No connection to 'robocall' controversy: consultant

But Jim Ross, a Canadian consultant to the U.S. company, says the services it provided during the 2011 federal campaign here had nothing to do with the growing "robocall" controversy engulfing the Harper government.

Elections Canada issued a statement Friday saying it has now been contacted by 31,000 Canadians regarding alleged irregularities in last year’s election.

So far, those allegations include telephone calls to Liberal supporters on election day, directing them to incorrect or non-existent polling stations.

The Liberals also claim their would-be supporters were hit with late-night and other annoying automated calls during the campaign, pretending to solicit support for the local Grit candidate but really intended to turn people off the party.

Ross served as campaign manager for St. Catharines MP Rick Dykstra, one of the 14 Conservative candidates who enlisted Ohio-based Front Porch for so-called "tele-town-hall" events.

Ross says the company would simultaneously call "maybe 10,000" potential voters in a riding, and invite them to participate in a kind of mass-conference call with the Conservative candidate.

Ross says, on average, about 15 per cent of voters called actually participate in a telephone town hall.

"People really like these events," he says, adding they are also relatively inexpensive.

Documents show Peterborough MP Del Mastro’s two telephone town halls, for instance, cost his campaign $2,700 each.

If nothing else, the role of Front Porch in the last election offers a rare glimpse into the ties between the Harper Conservatives and right-wing Republican political operatives south of the border.

Front Porch doesn’t hide its allegiance to all things conservative.

"Our passion is helping Republican candidates, elected officials, and conservative causes win by personally connecting them with voters and constituents," the company says on its website.

The website features a gushing report on Harper and the Conservatives winning last year’s election, calling the prime minister "the most powerful conservative leader in the Americas."

On its role for the Harper Conservatives during last year’s federal election, the firm boasts: "Front Porch Strategies won all 14 of their races."

Greg Weston can be reached at greg.weston@cbc.ca