A photo agency that took pictures of the Duke and Duchess of Sussex during what the couple said was a dangerous car chase has refused to hand over the images to them.
Backgrid told BBC News it had rejected a legal demand to share the material taken in New York on Tuesday night.
In a tongue-in-cheek response, the agency’s lawyers said Americans had long ago rejected “royal prerogative”.
The BBC has asked the couple for comment.
Conflicting accounts of what Harry and Meghan’s spokesperson described as a “near catastrophic car chase” resulting in “multiple near collisions” have emerged since the incident was made public on Wednesday.
New York police said “numerous photographers” had made the couple’s journey from an awards ceremony on Tuesday evening “challenging”, but added there had been “no reported collisions, summonses, injuries, or arrests”.
A taxi driver who briefly drove them suggested their spokesperson’s account was “exaggerated”, while some photographers involved have denied parts of it.
Backgrid, a California-based entertainment picture agency, said on Thursday it had received a letter from the Sussexes’ legal team.
It said the letter, which the BBC has not seen, stated: “We hereby demand that Backgrid immediately provide us with copies of all photos, videos, and/or films taken last night by the freelance photographers after the couple left their event and over the next several hours.”
The agency said it had replied in a letter: “In America, as I’m sure you know, property belongs to the owner of it: Third parties cannot just demand it be given to them, as perhaps Kings can do.
“Perhaps you should sit down with your client and advise them that his English rules of royal prerogative to demand that the citizenry hand over their property to the Crown were rejected by this country long ago.
“We stand by our founding fathers.”
In the UK there is no royal prerogative and there has long been tension between the Royal Family and the British media over privacy.
Backgrid said on Wednesday it was investigating the conduct of four freelance photographers involved in taking images of the Sussexes, even as the agency disputed the couple’s characterisation of the incident.
The photographers felt the couple were never in “immediate danger at any point”, according to the agency.
During the pursuit, the car carrying the duke and duchess, her mother and a security guard diverted to a nearby police station twice.
BBC News interviewed a taxi driver, Sukhcharn “Sonny” Singh, who was briefly involved in the pursuit. He said his cab was hailed from a police station.
They only drove a block when his taxi “got blocked by a garbage truck and all of sudden paparazzi came and started taking pictures”.
Mr Singh was then asked to drive them back to the police station.
A spokesperson for the duke and duchess said the couple understood they are public figures but that interest “should never come at the cost of anyone’s safety”.
Prince Harry has spoken of his anger at the actions of the paparazzi over the years, comparing the photographers to “a pack of dogs” who hounded his mother, in a BBC documentary.
Diana, Princess of Wales, died from injuries she sustained in a car crash after photographers chased the vehicle she was in through the streets of Paris.
“To see another woman in my life, who I love, go through this feeding frenzy – that’s hard,” he said in the recent Netflix documentary, Harry & Meghan.