Engineer Paul Ambrose died when he was overcome by fumes as he installed medical equipment in a New York hospital.

It is thought Mr Ambrose, 25, of Welford Gardens, Abingdon, was overcome by odourless nitrogen gas as he worked in the Presbyterian Hospital, on Wednesday morning.

Six others were treated for dizzy spells and minor injuries. Mr Ambrose, who was based at Magnex Scientific, at Abingdon Business Park, in Blacklands Way, was installing a powerful superconducting magnet in a magnetic resonance imaging (MRI) body scanner.

Former colleague Barry Smith said: "I have seen him do that job many, many times. I have done that job myself many times. It is very straightforward, but we all respect the gas and know the dangers. The room must be vented properly. "He was a likeable guy and everybody got on well with him. "

GE Medical Systems spokesman Charlie Young, speaking from their American head office, said: "We are saddened by the death of Paul Ambrose and we extend our deepest sympathies to his family for their loss. The cause of the accident is unknown at this time and we are co-operating fully with the hospital officials and local authorities in New York to determine the cause. "This is the first accident of its kind in GE Medical Systems' 17-year history with MRI systems."

The procedure involved using liquid nitrogen to cool the equipment until it became magnetic. The nitrogen evaporates to gas and must be vented outside as it displaces oxygen, making the atmosphere toxic.

New York Mayor Rudolph Giuliani said: "The other workers very, very courageously went in and tried to save him."