HS2: Large hole opens above rail tunnel near Little Missenden

The hole has opened up in the ground near Little Missenden, Buckinghamshire

A large hole has opened up above a tunnel built for the HS2 high speed rail line.

A spokesperson for HS2 Ltd said the opening in the ground near Little Missenden, Buckinghamshire, was above part of the Chiltern tunnel.

It said they were engaging with the landowner and had notified the Environment Agency.

The spokesperson said investigations were ongoing but it was likely linked to "pre-existing ground conditions".

Campaigners against HS2 said the hole, which they said measured about 6m (20ft) in diameter and was 5m (16ft) deep, showed it was "time to stop digging".

The 10-mile (16km) Chiltern tunnel is the longest on the HS2 project, which is designed to improve links between London, Birmingham and the north of England.

HS2 Ltd said the site had been sealed off and "there is no risk to the public".

HS2 Ltd said the hole had appeared above part of the Chiltern tunnel

Giant tunnelling machines have been excavating the high speed rail project's route under the Chilterns in Buckinghamshire for the past 21 months.

The two tunnels, which are between the M25 and South Heath, have five shafts for emergency access and/or ventilation near Chalfont St Peter, Chalfont St Giles, Amersham, Little Missenden and Chesham Road.

They are part of first phase of the route between London and the West Midlands, expected to begin operating between 2029 and 2033.

Eventually the route will link to Manchester, and potentially beyond.

The project has faced criticism about the impact it would have on the land the route would take, with campaigners fighting against plans to build on woodland.