FEARS that the Tesco tunnel in Gerrards Cross had collapsed for a second time brought trains on the line to a standstill on Wednesday afternoon.

Commuters travelling from Marylebone Station towards Birmingham at 12.30pm were stopped at West Ruislip station after a railway worker raised the alarm of a possible second collapse of the tunnel following the cave in on June 30. Network Rail were quickly on the scene but reported a false alarm.

A spokesman for Chiltern Railways said: "Network Rail have been on site and declared the tunnel is totally safe."

Fears of a collapse had arisen because sunlight was seen streaming through parts of the tunnel roof.

However Chiltern Railways said that due to the nature of the tunnel construction this is to be expected. The spokesman said: "The tunnel is built in sections and there is going to be sunlight where the roof has not yet been replaced.

"However the tunnel is perfectly safe."

The line was closed for 40 minutes in both directions as the tunnel was inspected.

Nina Seth, 31, from Chalfont st Peter, was on a train returning from London when she was told there had been a tunnel collapse at Gerrards Cross. She said: "We were stranded at West Ruislip station. The staff themselves seemed confused and didn't really know what was going on."