Co-operative Farms installed an otter holt at Coldham Farm near Wisbech after otter spraint (droppings) were discovered on the riverbank of the farm.

Footage released today by Co-operative Farms shows at least one otter, maybe two, making use of the holt which was only installed in July.

But otters have not been the only visitors - rats, spiders and a woodmouse have also filmed inside the holt.

Tom Paybody, Assistant Manager of The Co-operative's Coldham Farm, said: 'The fact that otters have already taken up residence in the holt is amazing news, as it can often take years for an otter to inhabit a man-made holt.

'We are not sure whether it is one otter or possibly two otters but the holt is now a hive of activity.'

Otter numbers have declined in this country since the 1960s, due to depletion of their natural habitats on riverbeds, but are now increasing again. Man-made holts now provide an ideal home for them while their natural habitats recover.

Farm manager Russell Armstrong and otter expert Cliff Carson found a suitable location for the holt.

Mr Carson, an environment officer from Middle Level Commissioners which is responsible for the river, found an otter spraint (otter droppings) on the riverbank of the farm and suggested that otters were interested in the location.

Mr Paybody said: 'The otters have obviously found a haven from the cold, but their presence also proves that the location for this holt was perfectly chosen. The good news suggests that the Coldham farm will celebrate the arrival of many more otters.'

The holt is constructed of breeze blocks and paving slabs and is built to last 20 years or more. As it is built into riverbank all that is visible on completion are two entrance pipes at the waters edge.

Motion cameras have been fitted so that Co-operative Farms can monitor any activity within the hold and sure it is providing the best conditions for any otters choosing to move into it.