Former Best Buy CEO Brad Anderson donated $25,000 to a conservative political advocacy group involved in an anti-Muslim social media campaign during the 2016 presidential campaign.

A venture capital group associated with Best Buy founder Richard Schulze also contributed $25,000 to the group, Secure America Now, which produced a string of ads that attack “radical” Muslims, including one that portrays the “Islamic States of America,” where Muslims have taken over the U.S.

The contributions have sparked controversy for Minnesota’s third-largest corporation and other companies to which Anderson and Schulze have ties. The Mayo Clinic confirmed Friday that it had accepted Anderson’s offer to resign from its board of directors because of the revelation.

Anderson said he was “completely shocked” when he learned that Secure America Now was involved in the anti-Muslim social media campaign. Anderson said he gave to the group because he shared its position on protecting Israel. “I never had any anti-Muslim desire,” Anderson said in an interview from his Florida home. Anderson said he will not be donating to Secure America Now in the future.

Olympus Ventures issued a statement Friday saying it was unaware of Secure America Now’s anti-Muslim social media campaign. It did not say why it chose to give the group $25,000 or who made the decision.

“Olympus Ventures, which manages Dick Schulze’s investments, made a single contribution to Secure America Now in 2016,” the statement said. “We were unaware of these ads which this organization funded until Wednesday. We informed Dick, who strongly condemned them and directed Olympus Ventures to cut off any further contributions to this organization or any organization which promotes hatred.”

Secure America Now’s largest donations, according to a 2016 tax returns obtained by the Center for Responsive Politics, included $2 million from Robert Mercer, a major supporter of Breitbart News, a conservative media outlet once run by Trump senior adviser Steve Bannon. Mercer also supported Trump’s eventually successful bid for election.

A New York accounting firm listed on the Secure America Now tax return as representing the group did not return a phone call seeking comment.

The Center for Responsive Politics, which first reported the contributions Thursday, said the anti-Muslim ads were part of a low-profile campaign to get votes for Trump in key states. Secure America Now YouTube videos show that the group has mounted social media attacks on what it calls “radical Muslims” for years. Friday, the group’s main website opened with a video that warned “The Muslim Brotherhood is one step away from sabotaging Western Civilization.”

The Minnesota chapter of the Council on American-Islamic Relations (CAIR) is calling for Anderson to resign from the boards of General Mills and Minnesota Public Radio because of his affiliation with what CAIR considers a hate group.

Anderson told the Star Tribune that he would leave his future on those boards up to his fellow directors.

In addition to running Best Buy from 2002-2009, Anderson served on the company’s board from 2013 to 2016 after leaving the CEO post. Anderson currently has no official position with the company.

“Best Buy unequivocally values diversity and religious tolerance, within our company and in the communities in which we work and live,” the company said in a statement Friday.

Schulze stepped down as chairman of Best Buy’s board in 2012 after an internal investigation found that he knew about a former chief executive’s improper relationship with an employee but did not report it to the board. He then attempted a hostile takeover of the company, but eventually abandoned that effort and endorsed the leadership of CEO Hubert Joly. As part of his reconciliation with the company, Schulze was given the title of “chairman emeritus” at Best Buy, an advisory position with no formal role. He was also given the right to have two representatives on the board, which included Anderson, but that provision has since expired.

Schulze hasn’t been involved in the day-to-day operations of Best Buy for years.

Olympus Ventures LLC is closely tied to the Richard Schulze Family Foundation, a philanthropic group. The two organizations share at least one senior executive, Kevin Bergman, and an office address in Minneapolis.

The Schulze Family Foundation’s board includes a former University of Minnesota president and high-ranking members of the Mayo Clinic. Associations with a controversial group like Secure America Now could tarnish the foundation’s reputation, specialists in branding and public relations said.

Schulze and Anderson have each given well over a quarter-million dollars to conservative political action committees and Republican candidates over the years. Both gave to former Gov. Tim Pawlenty’s Freedom First PAC when Pawlenty was gearing up for an ill-fated stab at the 2012 Republican presidential nomination. Each gave thousands of dollars to socially conservative Minnesota Rep. Michele Bachmann.

But the link of high-profile members of Minnesota’s corporate and philanthropic communities to a group like Secure America Now is a taint on Anderson’s and Schulze’s personal brands “that can spill over on to close friends and relatives,” said University of Minnesota brand specialist Akshay Rao.

Even if Anderson and Schulze were not aware of the anti-Muslim ads, public relations executive Glenn Karwoski of the Minneapolis firm Karwoski and Courage says the Schulze Family Foundation’s reputation is at stake, along with the reputations of General Mills and Minnesota Public Radio. The latter two organizations could see “negative reactions from consumers who buy General Mills products and MPR supporters,” Karwoski said, which is why he thinks Anderson will be asked to step away “very quickly.”

What happened with Anderson and Schulze also adds to the debate about the issue of “dark money” in politics. Anonymous and unlimited donations to nonprofit organizations that often indulge in attack ads can influence the outcomes of elections.

Current U.S. campaign finance laws would normally have blocked the public from ever learning about Anderson’s and Olympus Ventures’ contributions to Secure America Now. As a nonprofit, the group must make its overall revenue and expenses public, but individual donors are allowed to remain anonymous. Secure America Now inadvertently released its full tax return to the Center for Responsive Politics.

Anderson said he did not recall if he was told his donation would be kept confidential.

In its statement, Olympus Ventures did not say whether it expected its donation to remain anonymous.