Ian Brodie, Prime Minister Stephen Harper's chief of staff, watches from the back of a room during a photo op before the government caucus meeting on Parliament Hill on Wednesday. ((Tom Hanson/Canadian Press) )

Sources accused Prime Minister Stephen Harper's top aide of leaking information about Barack Obama's controversial NAFTA views on Wednesday, just as the prime minister himself was vowing to find out exactly who was behind the leak.

CBC News confirmed Wednesday that Harper's chief of staff, Ian Brodie, was the source of what is now being dubbed NAFTA-gate.

Brodie allegedly told a group of CTV reporters that Obama advisers had privately told Canadian diplomats that Obama's promise to reopen the North American Free Trade Agreement was just empty talk aimed at winning votes in Ohio.

Since 75 per cent of Canadian exports go to the United States, news that Obama, a front-runner in the race to be the Democrat's presidential candidate, would be interested in renegotiating the free-trade agreement would be of concern to Canadians.

Brodie's alleged disclosure occurred as he and the CTV reporters and employees were hunkered down in a room in Ottawa on Feb. 26, reviewing the contents of the federal budget.

Brodie allegedly also discussed musings by Obama's Democratic rival, Hillary Clinton, saying people from her camp also told Canadians to take her NAFTA concerns with a grain of salt.

CTV News went to air with the information on Feb. 27, focusing on the Obama side of the story, and it caused an uproar in the United States. Clinton accused Obama of double-talk, while the Republican front-runner and now nominee, John McCain, said Obama wasn't a straight-talker.

A CTV reporter told CBC News on Wednesday that Brodie was, in fact, the source behind the network's report. ABC News suggested as much earlier this week.

But the Prime Minister's Office on Wednesday night told CBC News that Brodie does not remember directly discussing either Obama, or Clinton, in the budget lockup.

A second leak arose

Soon after the leaked information emerged, and was promptly denied by Obama and the Canadian government, someone leaked a diplomatic memo to the Associated Press describing a conversation between Obama's economic adviser, Austan Goolsbee, and Canadian Consul General Georges Rioux.

The memo, written by a consular employee, says Goolsbee privately told Rioux that Obama's attack on free trade is "more reflective of political manoeuvring than policy."

In the House of Commons on Wednesday, Harper condemned the leak of the memo.

"This kind of leaking of information is completely unacceptable and, in fact, it may well be illegal," Harper said.

"It is not useful, it is not in the interests of the government of Canada, and the way the leak was executed was blatantly unfair to Senator Obama and his campaign."

The leak came in the final days before Tuesday's primary in Ohio, where voters are concerned about the impacts of NAFTA on their state's economy. Obama ended up narrowly losing the primary to Clinton.

Harper told the House that the Clerk of the Privy Council is working with the Foreign Affairs department to conduct an "internal security investigation" to find out who was behind the leak and that the government will take "any action that's necessary."

Layton calls for RCMP investigation

But NDP Leader Jack Layton demanded that Harper investigate the source of the first leak as well, the alleged Brodie leak.

"What about the first leak, the leak that actually caused this entire international incident?" Layton asked during Question Period in the House of Commons.

Layton later told reporters that he wants the RCMP to investigate the matter.

"The Conservatives can't be trusted to investigate a leak inside their own organization," he said. "They'd be investigating themselves, and quite clearly this leak produced consequences that no doubt, they are celebrating."

Liberal foreign affairs critic Bob Rae said on his blog Tuesday that it was clear the Tories were trying to help Republican friends at the expense of Canadian interests.

The controversy could play to the Republicans' advantage during the general U.S. election in November in Ohio, a potential swing state where job losses have made the 15-year-old free trade deal highly unpopular.

Liberal says Harper must clear up the matter

On Wednesday, Liberal MP John McCallum said the whole affair could leave a bad taste in Obama's mouth, should he be elected as the next president of the United States.

"The first day on the job, Mr. Obama looks across the northern border and what is he going to feel towards Canada? Something very bad if Mr. Harper is still in power and he hasn't cleared this up."

Over the course of the primary races, Obama and Clinton have both said they want to reopen the free trade deal between Canada, the U.S. and Mexico to ensure better environmental and labour standards.

International Trade Minister David Emerson and Finance Minister Jim Flaherty said U.S. officials should not forget the benefits of the agreement and hinted Canada could respond to a NAFTA pullout by renegotiating U.S. access to Canada's oil.

With files from the Canadian Press