The future of a partially built Tesco store in Gerrards Cross, Buckinghamshire, is in doubt after construction work caused a tunnel under the site to collapse.

The company has paid out £8.5m in compensation to rail passengers travelling between Birmingham and London since the tunnel was closed two months ago. They had an hour added to their journeys.

The Chiltern railway line, which links the cities, was back to normal this week after the Health and Safety Executive and two independent sets of engineers declared the tunnel safe. The HSE is investigating who was responsible for the collapse.

Investigations by tunnel contractor Jackson showed that the collapse of the £20.3m tunnel was caused by overloading soil on the top of the tunnel.

A Tesco spokesperson said that no decision had been made on the store, which is opposed by residents, Network Rail and Chiltern Railways.