Clinton’s campaign denies it invited Seddique Mateen to her Florida rally.

Seddique Mateen, father of Florida gay nightclub shooter Omar Mateen, was spotted standing in a crowd behind Clinton in Kissimmee, south of Orlando, on Monday night.

Normally, the people who stand behind a candidate at such rallies are selected by the local political organisation and Mateen himself told a local TV station: “I was invited by the Democratic Party.”

But once the news broke, Clinton’s camp said Mateen “wasn’t invited as a guest” by the campaign, which was unaware of his presence “until after the event”.

For 25 minutes, Mateen was captured on camera, smiling and holding a pro-Clinton sign as the Democratic presidential nominee paid tribute to his son’s 49 victims in the June massacre and then delivered her standard stump speech.

Mateen once proclaimed himself president of Afghanistan and declared in one of his bizarre YouTube videos: “Our warrior brothers in [the] Taliban movement and national Afghan Taliban are rising up.”

He also declared — after his son massacred patrons at a gay nightclub — that God will “punish homosexuals”.

Mateen told news outlets after the rally that he loves “the United States”. Omar Mateen fatally shot 49 people and injured another 53 at Pulse nightclub on June 12. He was killed by law enforcement officers following a three-hour standoff.

Mateen pledged allegiance to Islamic State in phone conversations with law enforcement negotiators. The father says his family has been co-operating with investigators.

During her speech, Clinton expressed support for the survivors of the attack and the loved ones of those killed.

“Bill and I were in Orlando about two weeks ago, and we had a chance to sit down with Mayor Dyer, other elected officials, members of the clergy, of the brave police officers who rushed into the Pulse nightclub massacre to save lives,” Clinton said, according to a transcript released by her presidential campaign.

“I just have to tell you how grateful I am for the leadership and the people of Orlando and Central Florida for your love and compassion. And I know how many people, loved ones and friends, are still grieving. And I want them to know that we will be with you.

“We will be with you as you rebuild your lives, as you rebuild hope for the future, because we can’t ever let that kind of hatred and violence break the spirit, break the soul, of any place in America.”

Mateen was spotted by local affiliate NewsChannel 5 WPTV of West Palm Beach. “We’ve been co-operating with the federal government, and that’s about it,” the father told the local station in a brief interview. “Thank you.”

Later, in another interview with the station, the father endorsed Clinton. “Hillary Clinton is good for United States versus Donald Trump, who has no solutions,” Mateen said.

“I … wish that my son joined the Army and fought ISIS. That would be much better.”

Omar Mateen also supported Hillary, according to a recent Washington Post article by the man who’d reported him to the FBI.

Mateen’s wife, 30-year-old Noor Salman, who was added to the gunman’s life insurance policy and given access to his bank accounts prior to the massacre, has also gone missing.

In a statement to the press, the Clinton campaign said: “The rally was a 3000-person, open-door event for the public. This individual wasn’t invited as a guest and the campaign was unaware of his attendance until after the event.”

The Clinton campaign did not respond to a request from the New York Post asking whether it accepted Mateen’s endorsement.

This is an edited version of an article that originally appeared on New York Post.