BATS and brown asbestos have led to an extra £66,000 bill for the demolition of a Burnley leisure centre, it has emerged.

Engineers could not begin to pull down the William Thompson Centre for 12 months after it was feared that bats were roosting in the building.

An investigation into the nocturnal creatures shed no further light on their presence, but Burnley Council leisure chiefs decided to play it safe.

Winston Robinson, a senior engineer at Burnley Council, said in a report to councillors: "The ecology survey was inconclusive and contradictory regarding the presence of bats.

"However, the report recommended the construction of a bat roost, in accordance with standard details produced by English Nature."

The ecological survey cost £1,525, and the roost itself was priced at just over £12,200.

Council chiefs originally wanted to pull down the centre in April 2006, but they couldn't move in until November when the bats left to hibernate. And, in order to comply with guidelines laid down by the Department of the Environment, the roost had to be in place by the following April, when the bats were due to return to the site, off Red Lion Street.

Coun Peter Doyle, the council's executive resources member, said: "There was an issue with the presence of bats at the William Thompson Centre, which we had to deal with, which caused delays to the demolition.

"We had to wait until the bats went into hibernation and, unfortunately, this resulted in extra costs, including the cost of building a bat roost. There was not a great deal we could do about it. The fines for accidentally destroying a bat roost are horrendous."

Bats are protected and often developers are required to undertake surveys, if their presence is suspected within a building.

Engineers also encountered problems with brown asbestos, which cost around £78,000 to assess, and remove.

The deadly material had been used in boarding above all the ground floor ceilings, and as fire protection to the structure's steelwork, members of the council's economic scrutiny committee have been told.

In-depth surveys on the asbestos could not be carried out until September 2006, when the centre had been shut and staff moved out.

Only a contingency clause in the demolition contract allowed the council to recoup some of its costs - of around £25,300 - bringing the final extra bill to £66,000.

Work on a new £200,000 pay-and- display car park, including 210 spaces, was completed in August. It was mostly built using recycled materials from the old leisure centre.