TORONTO -- A politician who helped lead the charge to expose problems at Ontario's troubled air ambulance service says he's now the subject of a smear campaign by an unknown adversary.

Progressive Conservative Frank Klees dismissed claims Monday that were made in a letter that calls into question his education and business background.

The unsigned letter claims Klees had business ties to publicly traded companies that were the subject of an investigation by securities regulators and to a man who was convicted of stock fraud.

It also suggests the seminary where Klees studied in the 1970s may not be a legitimate diploma-granting agency for Baptists.

The letter, titled "The Frank Klees Report," was mailed to The Canadian Press office in the Ontario legislature.

The letter said the information is in the public domain and suggests "a pattern of questionable educational background" and "undeniable business activities by Mr. Klees with dubious and illegal activities."

The information also "calls into question the ability of Frank Klees, MPP to question anyone's integrity," it states.

Klees said the letter is a smear that's meant to impugn his reputation and undermine his entire career, but he's confident that people will see through the false claims.

"There's a reason the person didn't sign it and the reason the person didn't sign it is because he would find himself in a great deal of trouble," he said. "Ninety per cent of that letter is false, totally erroneous information."

The letter comes as Klees continues his crusade to expose problems at the Ornge air ambulance service, which is under a criminal probe for financial irregularities.

He said he's also received threatening phone calls and letters threatening legal action against him for his work on Ornge. But he's not concerned about them, he said.

"None of that is deterring me," Klees said. "There's no question that there may well be individuals who are attempting to intimidate me."

He said he's never heard of some of the companies of which he's alleged to have served as a director.

The letter claims Klees had a diploma for a one-year program at the Toronto Baptist Seminary and suggests it may not be accredited. Klees said he holds a two-year theology diploma and a registrar at the seminary confirmed it is a degree-granting institution.

Klees also dismissed the letter's suggestion that he fudged his resume by claiming he was a player agent for football players in the NFL and CFL for eight years.

The "long list" of players he signed to football teams include Chris Schultz, Craig Ellis and Hank Illesic, he said.

Klees said the letter also misrepresented Municipal Gas Corp., a company he helped found, by saying it engaged in the door-to-door sales of energy contracts. In fact, the company did business exclusively with municipalities and institutions, he said.

As for the insinuation that he had ties to individuals involved in a stock fraud scheme, Klees said: "There is not one court record of my name being associated in any way with any of that."

"The bottom line is, obviously someone has an agenda," he said.

Klees will spend the next three days questioning witnesses that are expected to testify before a legislative committee that's looking into Ornge. Among them is Health Minister Deb Matthews and former Ornge chairman Rainer Beltzner.

Ornge, which receives about $150 million from the province, has been mired in controversy over sky-high salaries for its CEO, questionable business deals, poorly designed medical interiors in brand-new helicopters and allegations that public money may have been used for personal gain.

Auditor general Jim McCarter has criticized the governing Liberals for failing to oversee Ornge, despite giving it $730 million over five years and allowing it to borrow another $300 million.