Second in line to the throne William was left concerned by the threatening behaviours, his spokesman, Paddy Harverson, said. He added that the events seemed incomprehensible at this particular time.
The incident happened in a week which saw the start of the inquest into the death of William’s mother, Diana, Princess of Wales, whose car crashed in Paris in 1997 as she was being followed by photographers.
Prince William and Ms Middleton, who have rekindled their relationship after splitting up earlier this year, were leaving London’s Boujis nightclub in the early hours of the morning.
Mr Harverson said: “Prince William was concerned by the threatening behaviour of the paparazzi in London last night. Having already been photographed leaving the club, he and Kate Middleton were then pursued in his car by photographers on motorcycles, in vehicles and on foot. The aggressive pursuit was potentially dangerous and worrying for them.”
The images of the couple were the first of them out together since their split in April.
They got back together soon after and had managed to keep a low profile up until now.
Prior to their break-up, the pair were widely expected to get engaged.
The Press Complaints Commission is aware of the matter, Mr Harverson said.