A digger has become stuck in the silt-filled pond it is supposed to be repairing.

Work was being done to “desilt and repair” the Doctors Pond in Great Dunmow, Essex, when the excavator sank, the town council said.

It reassured residents “every effort” was being made to rescue it “as quickly and safely as possible”.

“The town council is working closely with contractors and specialists to minimise any potential disruptions,” a statement said.

The Doctors Pond, in the town centre, is reputedly named after an 18th Century doctor who bred leeches and kept them in the pond for medical use.

It is also claimed to have been the location where Lionel Lukin, the inventor of an unsinkable lifeboat, first tested out his creation.

The desilting project was estimated to take between three and four weeks when it started in October, but soon ran into delays.

“I cannot remember seeing a worse shambles than this,” said resident Tony Clarke, who moved to Dunmow in 2004.

“The council could be responsible for running up a very big bill indeed to put this matter right.”

Fish were safely removed from the pond at the start of October, with fencing installed and the water pumped into the River Chelmer.

However, “environmental pressures” and “logistical challenges” stalled the project, which the council said required a “significant financial investment”.

Mr Clarke, a builder and civil engineer, said in his opinion there was no quick fix to the stuck-in-the-mud digger.

He said the contract to complete the project, including extensive remedial works to surrounding public open spaces, could “now take many months”.