Please turn on JavaScript. Media requires JavaScript to play. Advertisement

A leading US scientist whose work helped lead to the development of the anti-impotency drug Viagra has died.

Robert Furchgott shared a Nobel prize in 1998 for work showing that the gas nitric oxide played an important role in the cardiovascular system.

The discovery that the gas could help enlarge blood vessels was a factor in the development of Viagra by the US pharmaceutical company Pfizer.

Mr Furchott's family announced he had died in Seattle on Tuesday. He was 92.