William Corbett, chief enforcer of Canada's election laws, has resigned in the midst of a major investigation into misleading robo-calls during the last federal vote.

Elections Canada spokesman John Enright said Thursday it was Mr. Corbett's decision to retire after five years as Commissioner of Canada Elections.

He will be replaced by Yves Côté, a long-time bureaucrat who most recently served as associate deputy minister of justice. Prior to that, he served as ombudsman for the Department of National Defence and the Canadian Forces.

Story continues below advertisement

The Harper government, which has been critical of the commissioner's pursuit of alleged electoral wrongdoing by the Conservatives, had no role in Mr. Corbett's departure or in choosing his successor.

Mr. Enright said Mr. Côté was appointed on merit by Marc Mayrand, the independent chief electoral officer, after a competitive process.

The commissioner is responsible for ensuring compliance with and enforcement of the Canada Elections Act.

Mr. Corbett has been at the centre of a complex investigation into allegations of misleading live and automated phone calls to voters during the 2011 election. The investigation centres on Guelph, Ont., but thousands of voters across the country have complained they also received calls directing them to non-existent or wrong polling stations.

The investigation continues but has so far concluded that someone using the name Pierre Poutine, an untraceable cellphone and a phoney Quebec address used an Edmonton-based automated service to make the misleading calls in Guelph.

Recipients of the calls tended to be voters who'd previously told Conservative organizers they did not intend to vote for the governing party.

Mr. Corbett has also been responsible for another continuing investigation, this one into Tory MP Dean Del Mastro, the government's primary defender against allegations of unethical conduct in the robo-call affair.

Story continues below advertisement

The Peterborough, Ont., MP is under investigation for allegedly exceeding his spending and donation limit during the 2008 election. One of Mr. Corbett's investigators has accused Mr. Del Mastro in court documents of knowingly filing a false return with Elections Canada and making an illegal donation to his own campaign.

Mr. Del Mastro has denied the allegations and has questioned why the independent electoral watchdog undertook the investigation without talking to him or informing him.

The Conservative Party was in Mr. Corbett's cross-hairs for most of his term as commissioner. He was responsible for the investigation into the so-called in-an-out affair, which included an unprecedented raid on Tory party headquarters.

The affair involved a complicated scheme to funnel money for national campaign ads in 2006 through dozens of local candidates, allowing the party to exceed its spending limit and allowing candidates to claim rebates on expenses they hadn't actually incurred.

The Tories fought the matter in court for several years, bitterly accusing Elections Canada of being biased against them and exceeding its authority. However, last fall the party and its fundraising arm eventually pleaded guilty to two counts each of violating the Canada Elections Act, agreeing to pay maximum fines totalling $52,000.

Whether Mr. Côté will be as aggressive as Mr. Corbett in pursuing alleged wrongdoing remains to be seen.

Story continues below advertisement

When he quit as ombudsman for the defence department in 2008, he received a lukewarm send-off from Esprit de Corps, a magazine for members of the armed forces.

The magazine said Mr. Côté had not been as high profile or as adversarial toward the chain of command as his predecessor, Andre Marin. As a result, it said Mr. Côté "never achieved much stature among the troops."