A man has been filmed screaming at a family that he wants them "dead" in an apparent act of road rage.
Driver Louise Small, 33 said she was threatened by former BBC producer Fergus Beeley in a Sainsbury's car park off the M27 in Hampshire on Saturday.
Her 50-year-old mother, 14-year-old son Joshua and partner Simon Gale, 33 were also in the car.
It followed a two-car crash involving the family's Mazda at about 11:30 BST. Police said no arrests had been made.
'Get back before you die'
No-one was injured in the collision.
During the heated exchange Mr Beeley told the family he was "trying to stop a death on the roads".
He said he was placing the family under a citizens arrest and added: "I do want you dead.
"In fact I want you dead right now. Get back in your car before you die."
Mr Beeley, whose car was not involved in the crash on the M27, said he had intervened "because people nearly lost their lives on the motorway".
'He just flipped'
Ms Small said she believed the other driver involved in the crash was Mr Beeley's wife who was travelling in a separate car.
Ms Small said: "He opened the passenger side door and he just flipped - he was just so crazy - he just ranted at my mum.
"I stayed in the car in case he tried to grab my son."
The family from Salisbury had been travelling to Portsmouth for a day out, but abandoned their plans after the heated exchange.
Mr Beeley, who has worked on Sir David Attenborough's The Life of Birds, Planet Earth - The Future, and BBC Natural World, has been contacted by BBC News for a response.
He has not worked with the BBC for 10 years and is not a BBC employee.
Hampshire Constabulary said the non-injury crash had involved a Mazda 3, a Peugeot 107 and a Skoda Octavia.
A spokeswoman said nobody had been arrested but an allegation of common assault was subsequently made by a 33-year-old man from Southampton and a 54-year-old from Gloucestershire.
Advice was given to both parties and they were told the two assaults would be recorded and filed.