Using funds awarded to the St Neots Green Corridor Project Team, an environmental body set up by the St Neots Town Centre Initiative, the volunteers will build an artificial otter home, known as a holt.

Otters are largely nocturnal animals, so a holt will provide a place for them to shelter during the day and perhaps to breed.

Volunteers from the friends group will carry out some of the work as part of their regular weekend working parties throughout the winter.

The team from RWE npower is coming to the reserve for the first time and will complete the construction as part of their programme of work with conservation groups to improve the local environment.

Senior ranger at the reserve Jim Stevenson said: "Otters are making a welcome return to the area after being locally absent for the past 30 years, but they need all the help they can get.

"This year, no less than 14 have been killed in Cambridgeshire, six of them in illegally-set crayfish traps.

"This Landfill Tax credit scheme award, and the efforts of the volunteers, will give our otters a much better chance of thriving in the St Neots area."