Hillary Clinton’s campaign offices around the country have been put on alert after at least two women approached Iowa staff under the guise of being supporters in an apparent effort to catch the campaign engaging in improper or illegal activity, a Clinton campaign official said.

The motivations of the women is not known, but their alleged techniques match those of Project Veritas, the conservative group run by James O’Keefe, which specializes in undercover stings meant to embarrass liberal groups and politicians. The group declined to comment on the Clinton campaign’s allegations. “Project Veritas does not comment on investigations, real or imagined,” said Daniel Pollack, the director of communications for the group.

A Clinton campaign official alleges that the women engaged in several efforts to entrap supporters. In one scheme, described by Clinton staff, a woman attempted to pass a cash donation to Clinton volunteers and interns. In another, a woman approached the campaign on Aug. 19 and said both her parents had donated to Clinton the legal maximum of $2700 each and wanted to funnel an additional donation through their daughter, a violation of federal law. On Aug. 13, a woman claiming to be Canadian approached another Clinton fellow to ask how to falsify an address for a campaign donation.

In another instance, a woman volunteering with the Clinton campaign on voter registration efforts in Iowa City returned to the campaign’s office in Des Moines and asked whether it was okay that she refuse to register people who don’t support Clinton, the campaign official said. The Clinton campaign maintains that its policy is to register all voters, regardless of their preference in candidates.

The women presented themselves as Allison Holmes, Jess Koski, and Jess Jones, according to the Clinton campaign, which collected names, email addresses, and phone numbers for the women. All gave the same phone number, which is listed on the website for the University of Minnesota-based Students for a Conservative Voice. Messages left at the number by TIME requesting comment were not returned. The women did not identify themselves as part of O’Keefe’s group, the campaign said.

It is not clear if any Clinton staff or volunteers did anything improper or illegal in response to the approaches. A Clinton official said the campaign is confident it upheld the law. O’Keefe rose to fame in 2009 with edited videos appearing to show employees of the Association of Community Organizations for Reform Now (ACORN) encouraging criminal behavior, resulting in the freeze of federal funding to the organization.

Photos provided by the Clinton campaign appear to identify one of the women as Laura Loomer, who filmed a video earlier this year at Barry University, which appeared to show a college official backing the creation of a charity to funnel money to the Islamic State called the Sympathetic Students in Support of the Islamic State of Iraq and Syria. Attempts to reach Loomer through Veritas were not successful.

Loomer appears in the photos wearing a navy baseball cap with the Hillary Clinton logo attending a rally for Clinton on July 17 before the Iowa Democratic Party Hall Fame Dinner in Cedar Rapids. That’s where Clinton officials allege she attempted to make cash donations to the campaign. The Federal Election Commission bans aggregate cash contributions over $100 from a single donor, while anonymous donations in cash of more than $50 may not be spent on federal elections.

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