An alleged leak within the Canada Revenue Agency may have allowed rivals of B.C’s United Nations Gang to acquire confidential information to target its members, police say.

Mike Ryan, a retired inspector with the Organized Crime Agency of B.C., told CBC News it's not known whether the source of the leak was an outsider hacking into the tax agency's database or an insider working for gangs.

Ryan said he learned of the alleged leak through the Abbotsford Police Department in late 2007 — just before members of the United Nations gang, alleged to be one of the West Coast's most powerful criminal organizations, started to be targeted in a wave of violence that has peaked in recent weeks.

Canada Revenue Agency files contain personal tax information about Canadians including home and work addresses.

Ryan said he had to warn the Canada Revenue Agency its employees might be in danger, when serving documents on UN Gang members.

The UN Gang, angry over alleged leaks of confidential information on its members, has filed actions in the Federal Court of Canada against the minister of national revenue.

That case is expected to wrap up in April.

None of the allegations has been proven in court.

With files from the Canadian Press