The Hillary Clinton campaign disavowed support from the father of ISIS-inspired Orlando nightclub gunman Omar Mateen late Tuesday.

A campaign official told Fox News Clinton disagrees with the views of Seddique Mateen, who made a startling appearance at a Clinton rally in the Orlando area Monday. Mateen was seen cheering her on and waving an American flag in the background as she paid tribute to victims of his son’s terror rampage.

WPTV first noticed Mateen’s presence in the crowd. He told the station that Clinton was “good for national security” and “gun control laws.”

Though Mateen claimed he had been “invited” to the rally in Kissimmee, he also suggested the invitation may have come in the form of a mass email.

The Clinton campaign said earlier Tuesday they were not aware of his presence.

"The rally was a 3,000-person, open-door event for the public,” a campaign official told Fox News. “This individual wasn't invited as a guest and the campaign was unaware of his attendance until after the event."

Mateen’s appearance seemed to clash with her message as she thanked local leaders and officers who responded to the June shooting at Pulse Nightclub, which left 49 people dead. It was the worst terror attack on American soil since 9/11.

“I know how many people, family members, loved ones, friends are still grieving,” Clinton said Monday. “We will be with you as you rebuild your lives … because we can’t ever let that kind of hatred and violence break the spirit, break the soul of any place in America.”

As Clinton spoke, cameras caught Mateen sitting behind her and appeared to snap a photo at one point in the rally.

Adding to the bizarre appearance is the father’s own background, as someone who has voiced support for the Taliban and at one point declared himself the leader of a “transitional” Afghanistan government. According to reports, he hosts a TV talk show that airs in California and is aimed at Afghans living in the U.S.

After the shooting, Mateen also vehemently condemned homosexuality – but then suggested his son had no right to open fire inside the gay nightclub.

When WPTV first tried to interview him on Monday after his rally appearance, he said only that he’d been “cooperating” with the FBI.

But, according to the network, he wanted to give an interview when the reporter ran into him at a rest stop later that night. In the interview, Mateen claimed he had been “invited” by the Democratic Party.

But when asked if he was personally invited or received a chain email invite, he said, “I’m a member, so as a member I get the invitation, so it’s nothing particular about it.”

He said, “It’s a Democratic Party so everybody can join.”

He called Clinton “good for [the] United States versus Donald Trump.” As for his son’s actions, he said he wishes his son had joined the Army and fought ISIS.

“That would be much better," he told WPTV.

Fox News' Tamara Gitt contributed to this report.