A false ad purporting to be an endorsement by Senator Mitch McConnell for the impeachment of President Trump was left up on Facebook after McCain PAC president Stephanie Elliott reported it to the company on Tuesday.

The ad shows McConnell, who heads the Senate Republican leadership team, with a clear message that the Kentucky senator is backing the move. “Have a good day,” says McConnell as the video ends.

But on Wednesday morning, a spokesperson for the McConnell campaign said that the conservative senator “is not endorsing that in any way.”

Elliott is no fan of Trump. As president of McCainPAC — the main political action committee formed by the McCain family — she was on board the “NoKo: Will You Trump the Second Amendment to Save Our Country?” bus tour in early November to voice her displeasure about the president’s decision to withdraw the U.S. from the Iran deal.

But there’s something else about this ad that raises questions about its source.

In order to take action against ads on Facebook, the social media giant requires the identity of the person buying the advertisement. Activists like Elliott often report problematic ad to Facebook by identifying a specific IP address or bank account used to purchase the ad.

The account behind the ad that references McConnell’s supposed endorsement of impeachment has never disclosed the name of the account owner. While Facebook removes known bots — machines that buy and distribute deceptive ads — the company does not take action against individuals.

“It’s a black hole for a lot of the types of campaigns I deal with,” Elliott told The Daily Beast.

When Elliott flagged the ad as “misleading,” Facebook quickly took it down. But several hours later, another attempt to buy the ad was made using a new IP address and it popped up again.

The FBI is investigating how the Russian Internet Research Agency attempted to influence the 2016 election. The American media outlet Politico obtained documents, first published by Britain’s Guardian, showing that Russian trolls began gathering “soft data” on U.S. voters as early as October 2016. As the Washington Post reported, investigators are not looking to see who bought the troll farm’s ads.

Facebook could not be reached for comment on this article.

This news comes less than a week after hundreds of Facebook employees signed a letter demanding that the company do more to combat fake news. The company has been under intense scrutiny from Congress and the tech community since revelations that the Cambridge Analytica scandal, in which the company sold user data, relied on a system that wasn’t secure against hackers.