Elections Canada says the number of specific "robocalls" complaints it has received has gone from 700 to 800, and that people in 200 different ridings in every part of the country appear to have been targeted.

Appearing before the House of Commons for the first time since the scandal broke out, Elections Canada Chief Electoral Officer Marc Mayrand said Thursday that none of the so-called "robocalls" came from his organization.

"A single elector being misdirected . . . is a serious offence," he said.

Since the May 2011 federal election, many Canadians have complained that they received automated phone calls guiding them to the wrong polling station, or to one that didn't exist. Some said they received these calls after first getting a phone call to find out if they were voting Conservative.

Trying to persuade someone not to vote, or stopping someone from voting, is illegal under the Elections Act.

Mayrand said the calls targeted voters in all ten provinces and one territory, and expressed concern that so many people failed to report the problem until it surfaced in the media in February.

Elections Canada specifically asks political parties to avoid calling voters about their polling locations. In response to recent criticism that his office may not be equipped to handle such a large-scale investigation, he assured the committee he has the resources required for the probe.

Some critics, including the Liberal party, have called for a public inquiry into the automated calls.

The opposition parties have accused the Conservatives of being responsible for the calls, but Prime Minister Stephen Harper's government has denied the accusations. One Conservative staffer resigned after being linked to the robocalls.

"How likely is it that it's one rogue person who'd be behind this?" NDP MP David Christopherson asked Thursday.

The Tories accused the Liberals of making such calls themselves, including one recorded message sent to Guelph voters that attacked the Tory candidate's position on abortion. The recording did not specify that the call was being made on behalf of Liberal incumbent Frank Valeriote, who has since admitted to the abortion calls.

Before Thursday, Mayrand has said very little, other than to reveal Elections Canada was investigating potential violations in the riding of Guelph, Ont. While his appearance was hotly anticipated, it came with interesting timing -- as many of Ottawa's political reporters were already behind closed doors studying the federal budget, which will be released later Thursday.

Committee chair Joe Preston, a Conservative, said it was the only day the committee could fit in the appearance -- a claim political scientist Ned Franks met with skepticism.

Franks, a professor emeritus with Kingston's Queen's University, said it's unlikely it was a coincidence Mayrand's appearance happened on budget day.

"I don't know which the government wants to distract attention from, either robocalls or the budget, my suspicion is robocalls," he told CTV News Channel on Thursday. "These things don't happen by accident."

Mayrand will be back in front of the committee before Parliament breaks for the summer. His final report could take up to a year.

With files from The Canadian Press