Philadelphia ? A gun-control activist who championed the cause for more than a decade and served on the boards of two anti-violence groups is suspected of working as a paid spy for the National Rifle Association, and now those organizations are expelling her and sweeping their offices for bugs.

The suggestion that Mary Lou McFate was a double agent is contained in a deposition filed as part of a contract dispute involving a security firm. The muckraking magazine Mother Jones, in a story last week, was the first to report on McFate’s alleged dual identity.

The NRA refused to comment to the magazine and did not respond to calls Tuesday from The Associated Press. Nor did McFate.

The 62-year-old former flight attendant and sex counselor from Sarasota, Fla., is not new to the world of informants.

She infiltrated an animal-rights group in the late 1980s at the request of U.S. Surgical, and befriended an activist who was later convicted in a pipe bomb attack against the medical-supply business, U.S. Surgical acknowledged in news reports at the time. U.S. Surgical had come under fire for using dogs for research and training.

McFate resurfaced in Pennsylvania and has since spent years as an unpaid board member of CeaseFirePA and an organization called States United to Prevent Gun Violence. She also twice pushed unsuccessfully to join the board of the nation’s largest gun-control group, the Brady Campaign to Prevent Gun Violence.

“It raises some real concerns with the tactics of the NRA. If they’ve got one person, maybe they have more. If they’ve done this dirty trick, what else have they done?” said Paul Helmke, president of the Brady Campaign, which planned to search its offices for listening devices and computer spyware.

The Brady Campaign and other groups said they are also researching whether McFate’s alleged spying constituted a crime.

“Under some circumstances, it could be trespass,” said Laurie Levenson, a professor at Loyola Law School in Los Angeles and a former prosecutor. But “if they’re open meetings, it may be underhanded and sneaky; it may not be illegal.”

At States United, McFate served as federal legislation director, meeting with members of Congress on Capitol Hill and writing letters. Over the years, she also stuffed envelopes, attended rallies and took part in conference calls and strategy sessions.

In retrospect, Helmke said, he now realizes McFate stopped by the Washington office for meetings and conference calls that could have been handled by phone, and perhaps pushed too hard to join the board or lobby Congress.

But as for any secrets she might have been privy to, the gun-control groups said they have little to hide, since they put their message and information about their budgets on the Web.

The CeaseFirePA leadership plans a vote Friday on whether to expel McFate, a board member for seven years.

“I feel flattered that the NRA would feel that they would have to infiltrate Ceasefire of PA. Obviously, they’re hearing our footsteps,” said Phil Goldsmith, the group’s president. “Frankly, I think it’s a waste of their money. We don’t deal in state secrets.”