The campaign of Democratic challenger Abigail Spanberger announced on Thursday that it had discovered and removed an operative for James O’Keefe’s Project Veritas who had posed as a volunteer and infiltrated its staff.

The operative, who went by the name Monica Nelson, appears to have been Marisa Jorge, a New York-based official who has been previously exposed after embedding with other political campaigns. Justin Jones, Spanberger’s communications director, said that Nelson had been on the campaign as a volunteer for several weeks. She had shown up at the offices with the appearance of being pregnant and said she was bored at home and wanted to help out.

The campaign, which has an estimated 5,500 volunteers, brought her on board.

Jones said that others began to suspect that Nelson was working undercover when she kept peppering junior level staff members with mundane questions about where Spanberger stood on certain policy topics. Those questions appeared designed in a way to get an answer that contradicted Spanberger’s public positions. Nelson has also emailed staffers asking to get some time along with Spanberger, saying, in part, that the candidate, a former CIA agent, was a “role model” because she was “a mother of 3 all while running for political office.”

When they determined that Nelson was actually Jorge—by, among other things, asking her about her nonexistent social media presence—staffers asked her to leave. She did, Jones said. But instead of getting into a car, she walked about a half mile down a busy road and ran swiftly across traffic in order to evade campaign workers who had been walking with her to see where she would go.

“Dirty tricks like these are the worst part of politics, and this is exactly what Abigail is running to change,” said Dana Bye, Spanberger’s campaign manager. “While others may scrape the bottom of the barrel out of desperation, Abigail and our campaign will remain focused on talking to our neighbors on their doorsteps about the issues that matter to our community—that’s the campaign voters deserve and it’s the campaign that we believe will carry us to victory.”

Spanberger is in a tight election contest with Rep. Dave Brat (R-VA), despite running in a traditionally Republican district.

Asked for comment, an official with Project Veritas referred The Daily Beast to footage it had produced from its undercover operations. But the videos included no remarkable revelation. In one, a communications staffer reiterates that Spanberger doesn't support a border wall. In another, the same staffer makes clear that the staff has no involvement with George Soros, despite accusations that Democratic financier has worked behind the scenes to elected Democrats.

This isn’t the first campaign that O’Keefe has infiltrated. His group has targeted several Senate Democrats as well, often with attempts to catch campaigns taking policy positions privately that are at odds with those they espouse publicly.

—With reporting by Will Sommer