This is the dramatic picture taken just moments before a man threatening to kill himself was Tasered by police.

Police were involved in a stand-off with the 26-year-old, who was holding a Stanley knife to his neck, for more than half an hour, bringing George Street in Croydon to a standstill yesterday afternoon.

Okam Kazim, 34, witnessed the incident from across the road.

He said: "The man had the Stanley knife pointing towards his neck. He already had a few cuts on him and he kept shouting he was going to kill himself.

"PCSO's arrived first and then other officers came, but when the armed police arrived everyone was pushed back up the street.

"Two police officers approached the guy, one was talking to him with his hands up and the other stood nearby with a Taser behind his back.

"When he saw a gap in the situation, the officer just pulled out the taser and zapped him. He started screaming and the police handcuffed him and took him to the ambulance."

A shop owner, who did not want to be named, added: "The police told me to close the shop doors and I had to let three customers out via the back.

"A little later, I heard a bang and I thought the man had stabbed himself and collapsed, but I now know it was when he was Tasered."

The man was taken by ambulance to Croydon University Hospital suffering minor cuts to his hands and throat.

A police spokesman said: "The gentleman has been detained under section 2 of the Mental Health Act at a London hospital.

"In respective of the posession of an offensive weapon there will be no futher action."