The driver of a tube train that knocked down and killed an 86-year-old man did not realise he had hit anyone until minutes after the impact, an inquest has heard.

It was only when the driver of the following train saw an object she thought was a bag or rucksack but was in fact the body of George Gigg that his death at Southfields tube station was discovered.

Today an inquest at Westminster Coroners' Court heard Mr Gigg, from Wimbledon, had wandered onto the tracks before being killed on a wet night in November.

Coroner Dr Paul Knapman said there was no blame attached to the driver who struck the elderly man - and it was not possible to know whether Mr Gigg had committed suicide or become confused before walking in front of the train.

But he court heard Victoria Drive resident Mr Gigg, a retired clerk and widower, had suffered a hip injury after falling on ice in 2003 and since become frustrated by his worsening health and mobility .

PC Steve Tucker of the British Transport Police said the driver who hit Mr Gigg noticed his brakes had been tripped by an automatic safety system but did not know why, and he continued his journey after the impact.

The body was first spotted by the driver of the next train , who had been warned there might be an object on the tracks.

PC Tucker, who investigated the scene of the collision, said: "I've dealt with many cases where drivers fail to see or hear anything."

CCTV footage showed Mr Gigg, who walked with two sticks, had used his Freedom Pass to get onto the station platform at about 6.15pm on November 17.

He sat on a bench for a few minutes before walking off the end of the platform, and at about 6.35pm he was hit by the eastbound train as it pulled out of the station.

His body was discovered three carriage-lengths away from the end of the platform Dr Knapman recorded an open verdict of death by multiple injuries - and said that while he suspected Mr Gigg committed suicide, there was not enough evidence to be sure this was the case.