Prince Harry, Meghan and her mother were involved in a “near catastrophic car chase” involving paparazzi, a spokesperson for the couple has claimed.
The incident happened after the Duke and Duchess of Sussex attended an awards ceremony in New York on Tuesday.
In a statement, their spokesperson said the “relentless pursuit” lasted for more than two hours.
They added it resulted in “multiple near collisions”.
The BBC has not been able to independently verify the details.
In a statement, the New York Police Department (NYPD) confirmed an incident took place and said that numerous photographers “made their [Harry and Meghan’s] transport challenging”.
No injuries or arrests were reported, the police said. Buckingham Palace has not yet commented.
There are claims the chase involved half a dozen cars, with reckless driving including going through red lights, driving on the pavement, carrying out blocking moves, and reversing down a one-way street – as well as taking photographs while driving.
Details are emerging of what seem to have been chaotic scenes. The couple, plus Meghan’s mother Doria Ragland, tried to take shelter from the paparazzi by going to a Manhattan police station.
BBC News understands the pair were staying at a friend’s home, and did not return directly to avoid compromising their security.
There was then a plan to use a New York taxi, with a yellow cab flagged down and Harry, Meghan, Ms Ragland and a security officer getting inside.
But the vehicle and its occupants were spotted by photographers and they reverted to their own security vehicles.
Cab driver Sukhcharn Singh told the Washington Post he picked up the four passengers at about 23:00 local time just like any other fare.
Mr Singh said he never felt in danger during what he said was a 10-minute journey and would not “call it a chase”.
“They were quiet and seemed scared but it’s New York – it’s safe,” he said, adding he returned the passengers to the police station at the request of the security officer.
The couple use private security while in the US – but Harry is engaged in a legal battle in London over the use of Metropolitan Police protection while he and his family are in the UK.
“While being a public figure comes with a level of interest from the public, it should never come at the cost of anyone’s safety,” the couple’s spokesperson said.
“Dissemination of these images, given the ways in which they were obtained, encourages a highly intrusive practice that is dangerous to all involved.”
The awards ceremony they attended – the Ms Foundation Women of Vision Awards – was Harry and Meghan’s first public appearance together since the King’s Coronation earlier this month.
Meghan accepted an award at the event alongside LaTosha Brown, the co-founder of Black Voters Matter.
New York City Mayor Eric Adams told reporters that two police officers “could have been injured” and that it “would be horrific to lose an innocent bystander during a chase like this”.
While Mr Adams said he “would find it hard to believe” that a high-speed chase took place for two hours, even a 10-minute chase in congested New York would be “extremely dangerous”.
Duncan Larcombe, the author of the book Prince Harry: the Inside Story, told the BBC that it appears “something has gone extremely wrong” with Harry and Meghan’s security in the country.
“This will come as a huge surprise for people who used to look after Harry in the UK,” he said. “There are huge questions to be asked about whether the paparazzi can still operate in this way.”
Prince Harry’s mother, Princess Diana, was killed in a 1997 car crash in Paris while being chased by photographers.
In an interview with the BBC for the documentary Diana, 7 Days, Prince Harry referred to the paparazzi as “a pack of dogs” who constantly hounded his mother. “Every single time she went out there’d be a pack of people waiting for her,” he said. “I mean a pack of dogs, followed her, chased her, harassed her, called her names, spat at her, trying to get a reaction, to get that photograph of her lashing out.”
Prince Harry is currently involved in multiple legal disputes with the British tabloid press, including allegations of phone hacking and the unlawful gathering of information.
Earlier this week, a lawyer for the prince told a London court that he should be allowed to challenge a government decision that denied him the ability to pay for police protection while in the country.
The pair stepped down from royal duties and moved to the US in 2020 – a move they said was partly due to harassment from UK tabloids.
Prince Harry has described his battle to change the media as his “life’s work”. Next month he will appear in a London court to give evidence in a phone hacking case.