The chair of Canada's spy watchdog committee has resigned his position, the Prime Minister's Office confirmed Thursday, amid reports he had questionable ties to a lobbyist.

The resignation of Dr. Arthur Porter, chairman of the Security Intelligence Review Committee, comes after pressure from within the PMO, CTV Ottawa Bureau Chief Robert Fife reports.

This week, a National Post report revealed that Porter had forged a business contract with an international and controversial lobbyist.

Three years ago, Porter was appointed to the review committee. He assumed to position of chairman last year.

In a statement, Harper said that Carol Skelton would serve as interim chair until the vacancy is filled.

The SIRC is an independent review body that reports to Parliament about CSIS.