Dog walker Nicola Kennedy, 59, also saw the scene as it unfolded.
She told the Evening Standard: “When I came along it was already in the water.”
“As I walked beside it the alarm was going off, then the boot opened and the car sunk to the bottom of the Thames.
“It was quite extraordinary. Many people were taking pictures and the police were called but they couldn’t come out in time to rescue it.
“I have never seen anything like that and I’ve lived in Putney for 30 years.”
