OTTAWA - The federal government intends to revoke the citizenship of at least 1,800 people who allegedly used fraudulent means to become Canadians.

According to Immigration Minister Jason Kenney, most of the targeted individuals were counselled by three or four crooked immigration consultants on how to concoct fake proof of residency in Canada.

To become a citizen, a person is supposed to have lived in Canada for three out of four years.

"Sadly, there is an industry of what we call unscrupulous agents operating around the world who sell advice on how to take advantage of Canada to break our laws," Kenney said in the text of a speech delivered Monday to the Economic Club of Toronto.

"And there are some people — thankfully, I think a small minority — who are prepared to pay big money in order to falsely obtain Canadian citizenship."

In a later interview, Kenney said the vast majority of the 1,800 allegedly fraudulent citizenships were facilitated by three or four immigration consultants.

The consultants marketed their services to people living primarily in overseas tax havens or in certain Middle Eastern countries, where Kenney said a Canadian passport holder can earn double the salary.

Typically, he said the consultants provided receipts for apartment rentals and other faked evidence of residency in Canada while the applicant remained abroad.

During an extensive two-year investigation with the RCMP, Kenney said his department employed sophisticated computer technology to identify suspicious patterns in citizenship applications. Among other things, it uncovered one office address in Mississauga, Ont., which was listed as the home residence for over 300 applicants.

"We started to put together the patterns of questionable activities, questionable addresses, and we chased this stuff down and found that much of it was facilitated by the same handful of consultants."

Kenney said there are "ongoing criminal investigations" into the conduct of the consultants.

"I certainly hope that the book is thrown at those who profited from trying to sell Canadian citizenship illicitly."

As for the 1,800 individuals who took the consultants' advice, the government is now in the process of notifying them of its intention to revoke their citizenship. They have 30 days in which to respond.

Up to now, Canada has successfully revoked citizenship status — usually an arduous process involving lengthy court appeals — from only 66 people.

But Kenney predicted most of the 1,800 won't contest revocation since the evidence of fraud is "compelling" and most don't live in the country in any event.

"We've got them dead to rights ... We think most of them will put up the white flag."

Joshua Sohn, vice-chair of the Canadian Bar Association's immigration section, welcomed the crackdown but expressed some concern about the scale of the operation.

"I think it's a good thing that the government is signalling that it's going to take this seriously," Sohn said in an interview.

"It's a question of balancing that with some pragmatism as well."

Sohn noted that even the most straight-forward citizenship application takes about a year to process. And he expressed concern that the backlog might get worse if the government shifts resources to focus on mass revocation of fraudulently obtained citizenships.

"The 1,800 at once ... I do think that just raises pragmatic issues and whether resources are going to be tied up in that that are going to further delay citizenship processing."