The incident involved "a ring of highly aggressive paparazzi" in half a dozen cars with blacked out windows, driving dangerously and putting the lives of the couple and Doria Ragland in danger, according to Harry's spokesperson.
"This relentless pursuit, lasting over two hours, resulted in multiple near-collisions involving other drivers on the road, pedestrians and two NYPD (New York Police Department) officers," the spokesperson said in a statement on Wednesday.
The couple - the Duke and Duchess of Sussex - were shaken by the incident but otherwise unharmed.
The New York Police Department said it had assisted the private security team protecting them.
"There were numerous photographers that made their transport challenging. The Duke and Duchess of Sussex arrived at their destination and there were no reported collisions, summonses, injuries, or arrests," an NYPD spokesperson said.
The Washington Post quoted taxi driver Sukhcharn Singh, who said he drove the group and a security guard for around 10 minutes before returning to the police station he had picked them up from at the security guard's request.
"I don’t think I would call it a chase," Singh was quoted as saying, adding that two vehicles had followed them and come next to the car, taking pictures and filming.
"I never felt like I was in danger. It wasn’t like a car chase in a movie. They (the couple) were quiet and seemed scared but it's New York - it's safe."
Pictures on social media show Harry, Meghan and her mother sitting in the back of a New York taxi which their spokesperson said showed "a small glimpse at the defence and decoys required to end the harassment".
Media reported the couple had switched to the taxi to try and shake off the photographers, after the car they left the Ziegfeld Ballroom in midtown Manhattan in was pursued.
'Highly intrusive'
Harry (38) has long spoken out about his anger at press intrusion which he blames for the death of his mother Princess Diana, who was killed when her limousine crashed as it sped away from chasing paparazzi in a Paris tunnel in 1997.
The couple's spokesperson said the chase on Tuesday could also have been fatal and involved paparazzi driving on the sidewalk, running red lights and driving while taking pictures.
Those involved were confronted by police officers multiple times, according to the spokesperson.
Chris Sanchez, a member of the couple's security team, told CNN he was concerned members of the public could have been hurt.
"I have never seen, experienced anything like this," he said. "What we were dealing with was very chaotic. There were about a dozen vehicles: cars, scooters and bicycles."
New York City Mayor Eric Adams said he had received a briefing that two NYPD officers could have been injured in the incident.
"I don't think there's many of us who don't recall how, how his mom died," Adams told reporters. "And it would be horrific to lose an innocent bystander during a chase like this and something to have happened to them as well."
He said he would be given an in-depth briefing later, but that he found it hard to believe there would have been a two-hour high-speed chase.
"If it's 10 minutes, a 10-minute chase is extremely dangerous in New York City," Adams said.
The Ms. Foundation for Women, the organisers of the awards ceremony where Meghan (41) was honoured for her work, said it was horrified by the episode.
"Everyone, especially the media, must do better," the statement said.
Buckingham Palace also had no comment.
The duke and duchess, who live in California with their two young children, had been staying at a private residence but decided against returning there as they did not wish to compromise their host's safety, according to their spokesperson.
Harry has never hidden his dislike for the press, fuelled by the treatment his mother received and by his own experiences, particularly when he was young.
In his memoir Spare, the couple's Netflix documentary series and TV interviews, he has railed against British tabloid newspapers invading his and his family's privacy -one of the main reasons he and Meghan gave for stepping down from their royal roles in 2020 and moving to the United States.
Harry is currently involved in numerous court cases in London where he has accused newspapers of using unlawful methods to target him and his family. While papers reject nearly all his allegations, one publisher last week apologised for unlawfully seeking information about him in 2004.
Couple's relationship with media
Here is a timeline of Harry and Meghan's relationship with the media.
1997: Harry's mother, Princess Diana, is killed on August 31, 1997 in a car crash in Paris alongside her lover Dodi al-Fayed.
2004: Prince Harry scuffles with photographers outside a London nightclub.
2008: An inquest into Diana's death in 2008 concludes she and al-Fayed were unlawfully killed by the grossly negligent driving of her chauffeur Henri Paul and paparazzi photographers pursuing their limousine.
2016
July: Harry, fifth-in-line to the British throne, and Meghan, an actress from Los Angeles, begin their relationship.
November: Harry criticises the media for intruding into his girlfriend's private life, accusing some newspapers of abuse and harassment, some of which he describes as racist.
2018
May: The couple marry in the medieval chapel of Windsor Castle and become the Duke and Duchess of Sussex.
October: Harry and Meghan announce she is expecting their first child while in Australia on their first overseas tour.
2019:
March: Buckingham Palace announce Harry and Meghan will set up their own household, breaking from the operation they shared with his elder brother Prince William and his wife Kate. There are media reports of rifts between the two couples.
May: Meghan gives birth to a boy, Archie. The couple invite a small group of media to a photocall, prompting grumbling from parts of the press that had been increasingly critical of the couple.
October: Meghan says she is suing the Mail on Sunday newspaper for printing parts of a letter she wrote to her estranged father. Harry announces he is suing other papers over allegations of phone-hacking.
In a TV documentary, Harry discloses a rift with his brother William. He accuses the media of bullying, comparing it to their treatment of his mother, Princess Diana, before her death in a Paris car crash in 1997.
Meghan says life had been hard as a new mother dealing with intense scrutiny.
2020
January: The couple announce their intention to step back from senior royal roles and become financially independent. They agree to give up their "Royal Highness" titles and in March they move to California.
2021
February: Harry, who served in the armed forces for a decade, wins an apology and damages from the Mail on Sunday over an article claiming he had turned his back on the military.
A London High Court judge rules the same paper breached Meghan's privacy by publishing extracts of her letter.
Buckingham Palace says the couple's split as working members of the royal family is permanent and they will lose their royal patronages.
April: Harry returns to Britain for the funeral of his grandfather Prince Philip, Elizabeth's husband. Pregnant Meghan was advised not to travel.
May: Harry tells US chat show host Oprah Winfrey in an interview how he had turned to drink and drugs to numb the grief he felt over the death of his mother, killed when her car crashed as it fled press photographers. He says the fear the same might happen to Meghan was one of the main reasons they quit royal duties.
2022
January: Harry begins legal action to challenge a government decision that denied him police protection when in Britain. He later starts a libel claim against the Mail on Sunday over an article saying he had tried to keep the legal action secret.
June: Harry and Meghan return to Britain for celebrations to mark Queen Elizabeth II's 70 years on the throne. They are greeted with cheers and some jeers.
September: Harry and Meghan are in Britain when the Queen dies. They join William and Kate for a walkabout to meet mourners.
October: Harry joins singer Sir Elton John and others in suing the publisher of the Daily Mail newspaper, alleging phone-tapping and other breaches of privacy.
2023
January: Harry's memoir Spare is published, revealing intimate details of his relationships with King Charles and William. He later criticises press coverage of the book.
March: Harry makes a surprise appearance at London's High Court at the beginning of his lawsuit against the Daily Mail publisher.
May: Harry attends his father's coronation alone, with Meghan and his children remaining in the United States. He does not play any formal role in the ceremony.
