Donald Trump continues to insist that he once took a scary helicopter trip with former San Francisco mayor Willie Brown, even as Mr Brown dismissed the story as “fiction”.

But it turns out another California politician, Nate Holden, did accompany Trump decades ago on a turbulent chopper ride, US media report.

Both Mr Brown and Mr Holden are black.

The former president said during a news conference that he and Mr Brown had gone “down” in a helicopter together and Mr Brown had been “a little concerned”.

The story became an issue after Trump recounted it on Thursday, in response to a question about Mr Brown’s relationship with Kamala Harris. The pair dated in the 1990s.

Trump was asked whether he thought the relationship had played a role in Ms Harris’s career journey. At the time, Ms Harris was a prosecutor and in 2002 was elected district attorney in San Francisco.

“Well, I know Willie Brown very well,” Trump said, before speaking about his memories of the flight.

“We thought maybe this was the end,” Trump said. “We were in a helicopter… and there was an emergency landing. This was not a pleasant landing.”

He then claimed the former mayor had told him “terrible things” about Ms Harris.

“He had a big part in what happened with Kamala,” Trump said.

Mr Brown, 90, told US media he had never shared a helicopter with Trump, adding: “I don’t think I’d want to ride on the same helicopter with him.”

He also denied he said anything disparaging about Ms Harris.

“That’s so far-fetched, it’s unbelievable,” he told local TV station KRON. “I could not envision thinking of Kamala Harris in any negative way.

“She’s a good friend a long time ago, absolutely beautiful woman, smart as all hell, very successful, electorally speaking.

“He was doing what Donald does best, his creative fiction.”

Despite a flat denial from the former San Francisco mayor, Trump insisted the story was true in a call to the New York Times, saying he was “probably going to sue” without elaborating.

Campaign spokesman Steven Cheung posted a photo of a page of Trump’s book “Letters to Trump” showing the former president pictured with Mr Brown and including a caption mentioning the helicopter incident.

Meanwhile Mr Holden, 95, a former Los Angeles city councilman and state senator, told US media outlets he had a distinct recollection of a helicopter trip with Trump.

In the 1990s, Trump was attempting to develop property in Los Angeles.

Mr Holden said that they took a very turbulent helicopter ride around 1990, during a visit with Trump to his Atlantic City casino.

The helicopter experienced mechanical trouble and was forced to make an emergency landing in New Jersey.

Others speculated that Trump, 78, may have confused Willie Brown with Jerry Brown, California’s former governor, with whom he shared a helicopter in 2018 to visit the aftermath of the Paradise wildfires. Gavin Newsom, the current state governor, was also on the flight.

But both men told US media there had been no emergency landing or danger on that flight.

Trump’s remarks at an hour-long news conference at his Mar-a-Lago estate come as recent polls show him slipping against Ms Harris.

A survey conducted by the New York Times and Siena College from 5 to 9 August puts Ms Harris ahead of Trump by 50% to 46% in three key battleground states – Wisconsin, Pennsylvania and Michigan.

The RealClearPolitics polling average gives Ms Harris a slight edge in the popular vote, although Mr Trump retains a lead in a number of the most important swing states.