Staff at Chorley station had blanked the CCTV tape.

The men, all Bolton Wanderers fans, were caught on video tape last February assaulting a Manchester United fan at Chorley railway station, Lancashire.

But the CCTV footage was wiped accidentally by station staff.

However, the tape and video recorder were sent to the FBI headquarters in Virginia where scientists were able to restore the images.

Preston Crown Court heard three United fans were knocked to the ground and kicked repeatedly at the railway station.

They (The FBI) were able to examine and retrieve what was effectively a blank tape Insp John Vernon, British Transport Police

Steven Povah, 47, from Leigh, was knocked unconscious, spent several days in intensive care, and needed reconstructive surgery to an eye socket.

Mr Povah can only walk with the aid of a stick.

Nine men, all from Bolton, pleaded guilty to violent disorder.

Ronald Brickles, 31, and Anthony Charnock, 32, were both jailed for two and a half years and 44-year-old Malcolm Cooling was imprisoned for 12 months.

'Pack mentality'

The other six, Gerard Gallagher, 38, Timothy Hodge, 44, John Norris, 41, David Hough, 38, John Bennett, 38 and Anthony Bollard, 48, were given intermittent custody orders to serve time at weekends.

A tenth man, Paul Kirkwood, 43, was given 150 hours community service.

Judge Michael Evans said: "It is a tragic example of what can happen when otherwise respectable people have been inebriated by excessive amounts of alcohol and are carried away by herd instinct and pack mentality."

Inspector John Vernon of British Transport Police said the FBI's help had been "incredible."