The most seriously injured survivor of the July 7 bombings has spoken of how he was standing next to the terrorist ringleader as he detonated his device.

Daniel Biddle, 31, lost both legs, his left eye, his spleen and 87 pints of blood when Mohammed Sidique Khan killed himself and six other people at Edgware Road.

He told the inquests into the 52 who died in the 2005 atrocities that a 20p piece remains lodged in his thigh bone, and other shrapnel, including his door keys, was removed by surgeons.

Speaking at the Royal Courts of Justice, Mr Biddle said he was blown out of the westbound Circle Line train as he travelled to work as a construction manager.

He described how Khan, who got on the train at King's Cross, sat between 6ft and 10ft away from him before detonating his bomb by jerking a white cord.

Mr Biddle said: "The train entered the Tube tunnel, I looked around. As I looked around, he looked up and I saw a quick movement. Then there was a big white flash.

"The kind of noise you get when you tune a radio in. It felt like the carriage I was in expanded at a fast rate and then contracted quickly.

"And with that it blew me off my feet and through the carriage doors into the tunnel."

He added: "Before he set the device off he looked up and along the carriage and just looked down.

"He didn't say anything or shout anything I remember hearing. He got his head down, moved his arm and the next thing I am outside the train."

Mr Biddle said his first thought was that he had "fallen out of the train" when he woke up on the tracks, covered in debris.

He said: "I had quite a lot of metal on top of me. It was very dark and dusty.

"My initial thought was 'Jesus Christ, the doors have given and I have fallen out of the train'.

Mr Biddle described how he hit his head against a light on the wall of the tunnel, knocking him out.

When he came to, the train was still moving, and he found a piece of door or train panel holding him down by his legs and his arm was on fire.

The inquest heard that Mr Biddle could see several bodies, including one just 2ft away.

He said: "I was terrified, seeing what I had seen, and thought I was going to die. So I was screaming just as loud as I could to get help."