This follows fraud and theft charges being laid against a former citizenship judge for allegedly passing copies of citizenship exams to a Toronto-area immigration consultant.
The Mounties allege copies of the tests were used so that clients of a citizenship consultant could gain citizenship without meeting the proper requirements.
The RCMP say their one-year investigation was started after an internal immigration department fraud probe and were unable to say how many clients were allegedly involved.
The force says an immigration consultant and an employee of the consultant have also been arrested and charged.
Seventy-year-old Philip Gaynor, who was appointed a citizenship judge in Toronto in 2006, is charged with breach of trust, fraud and theft over $5,000, while Ling Li, 49, and Sui Zhun Mo, 58, are charged with possession of stolen property.
Gaynor, a Whitby, Ont., businessman, was reappointed to a second term in 2009 by Immigration Minister Jason Kenney and his mandate was completed last September.
Citizenship and Immigration Canada spokeswoman Nancy Caron called the charges "serious."
"We will take measures to address this, up to and including revoking the citizenship of anyone who obtained it fraudulently," Caron said.
To reduce the possibility of fraud the questions on the test are changed on a regular basis.
"We are moving to an online testing system where each test will be a random scrambling of questions, helping prevent the type of fraud alleged in this case," Caron said.