Investigators are probing how a 100-year-old tunnel network may have caused the giant sink hole in Hogg Lane.

A three metre “bottomless” sink hole opened up in front of a lorry on Wednesday afternoon as drivers watched in horror.

No-one was hurt in the incident, but authorities have since found a 'collapsed' tunnel under the sink hole.

The hole in the road has been described as at least 15 metres (or 50ft) deep, and "approximately the volume of two London double decker buses," by the council.

A spokesman for Thurrock Council said: "It would appear a 100-year-old tunnel below the road – linking Titan Pit with what is now Badgers Dene, has collapsed, but more work needs to be done to discover whether the tunnel collapse was triggered by the road issue, or vice versa."

Commentators on Facebook expressed concern, saying the tunnel is one of a century-old network of tunnels that runs under Chafford Hundred.

Richard Suttling writing on Facebook said: “There’s loads more under Chafford Hundred. We used to explore them as kids.”

Jenny Lynda Goldsmith wrote: “Let's hope they know about the ones at the entrance to Chafford - them and all the ones near the nature reserve. I suppose they don't know Chafford Hundred is built on chalk pits. God help us all.”

Trudie Duff wrote: "They were the tunnels with the old train tracks that lead to Grays beach, right under the new college! And yeah there were loads under the houses in the wharf area."

The council has said the road will remain closed to pedestrians and vehicles "until it is safe".