Developers were forced to spend more than £20,000 on a luxury heated bat house after the discovery of an endangered species.

Summerville Developments had hoped to demolish two houses and construct nine apartments in the High Street, Heathfield.

But the work was postponed for months after ecologists said they had found the droppings of a brown long-eared bat and demanded the bat house be built.

Geoffrey Key, managing director, of the Kent-based firm said he was frustrated that so much time and money had been spent on a bat that “no one has seen.”

He said: "If it were a bear or a gorilla or some serious endangered species perhaps I would view this differently.

“I just feel that perhaps we have gone a step too far in the protection of one bat which as of today no-one has seen.

“We've spent £20,000 to £30,000 building that structure for this phantom bat on the say-so of an ecologist who found some droppings in the house.”

Planning permission for the development of the Heathfield site was granted by Wealden District Council in August last year.

But work was halted as the developers carried out two surveys of the existing properties.

Ecologist Stephen Prosser, of Camber Ecology, confirmed the roof space was used by small numbers of common pipistrelle and brown eared bats.

In 2007 his report said he had found one legally-protected bat and about 800 droppings.

In his August 2008 survey he found nearly a 1,000 bat droppings in the attic and recommended a shelter was built.

Mr Prosser said: "The fact that they are fully protected immediately means you know there is a route you're going to have to follow.

"All bats are extremely important. They are biological indicators - if you have plenty of species of bat around you know you have good biodiversity."

The new shelter is five metres wide, five metres high and four metres deep.

Natural England provided the requirements for the new one-roomed structure to create a suitable roof space for breeding bats.

They confirmed it is an offence to damage, destroy or obstruct access to any place used by bats for shelter, whether they are present or not.

A fine of up to £5,000 may be issued for damaging a bat breeding site.