One of the firearms officers who chased Jean Charles de Menezes onto a tube train told today how he had to reload his weapon as he fired at point blank range at the innocent Brazilian because his gun jammed.

As the officer, known as Charlie 2, began to describe the fatal moment when the electrician was shot he said he wanted to acknowledge how distressing the process was for the family.

"Can I take this opportunity to acknowledge the family because I am very well aware of what we are going to describe and this is distressing for me and I completely respect and understand how difficult this is for them," he said.

"I would like to say I am a father and if he were my son I would be utterly devastated. And I would like to offer my condolences before I describe this thing that happened.”

The officer, who has been a specialist firearms officer for 17-years, told how he followed a colleague onto a northbound train at Stockwell tube station, believing they were following Hussain Osman, one of four failed suicide bombers who had tried to strike in London the day before, on July 21 2005.

Describing the moment he got onto the train and raised his gun he said: "At this point I was convinced that this man was a suicide bomber and he was about to detonate a bomb and blow us all up.

"I had the honestly held belief that unless I acted immediately I and other persons present were about to die and I formed the opinion that I had to shoot this man in the head and kill him instantly to prevent any detonation."

Alongside him on the carriage was another firearms officer, known as Charlie 12 and a surveillance officer.

As Charlie 2 got onto the train Mr de Menezes got up from his seat and started walking towards them before the surveillance officer grabbed him and pushed him back down on his seat.

Charlie 2 raised his gun, he told the inquest sitting at the Oval cricket ground, but did not remember anyone identifying themselves as police officers.

From behind a screen he said: "I ran forward and reached over the top of the surveillance officer and I pushed him down. I shouted 'armed police' and I held up the handgun to the head of the subject and I fired."

Asked why he shouted a warning at such a late stage he said it was out of training and to let members of the public know who he was.

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