A man used a kitchen knife to slice off his hand before it fell off in front of stunned onlookers, police have said.

The 23-year-old emerged from a public toilet in front of the High Road Seven Kings Car Park at about 3pm on Saturday with his right hand dangling from his wrist.

He then walked about 50 yards before sitting down.

As he walked, his hand fully detached itself from his wrist and fell into his jacket pocket, according to an eyewitness.

The man was taken to the Royal London Hospital, Whitechapel, where his injuries have been described as “life changing”.

It is not known why the man hacked off his own hand.

Gurpreet Sagoo, who had parked in the car park when the incident happened, said: “When I got to him he had lost a lot of blood and he was very pale.

“I’ve never seen anything like that in my life. I had no clue what to do. It looked pretty bad.”

Another eyewitness said: “There was so much blood on the floor. It was horrific.”

An air ambulance landed in the car park but the man was taken to hospital by road ambulance.