Sussex Police are suing a council after an air conditioning unit at its new £7.3 million police station was so noisy it had to be moved.

The unit made such a racket that employees and neighbours complained and it finally had to be moved to another part of Crawley police headquarters - at a cost of £100,000.

The extra work caused one of several project delays that are now part of a legal claim against East Sussex County Council, which designed the building.

The claim, running to a £250,000, is expected to be settled out of court once council insurers have examined the extra costs.

Sussex Police and the Sussex Police Authority, which paid for the station, are pleased with the building which opened in October 1998. But an authority internal audit showed that work on the building had over-run by almost 20 weeks.

East Sussex County Council had absorbed the costs of an initial five-week claim and another five weeks had been held to be the contractor's fault.

Design problems, including the positioning of the air-conditioning unit, were seen as a major cause of the delays.

Andrew Ogden, Sussex Police Authoritydeputy clerk and solicitor, said: "We will want to resolve the claim amicably, without the need to go to court.

"Every large project has snags and Crawley police station was no exception.

Our claim is under 10 per cent of the overall cost, not a vast sum but nevertheless important, and we have to sort it out.

"I think it is important to stress that from our point of view it is a good police station and everyone is pleased with it."

Work started on the new station in March 1996 and was expected to take 22 months.

There were delays constructing a 60-metre tunnel under Woodfield Road, linking the station with the nearby magistrates court. One problem involved joints in the tunnel which did not seal properly.

The station has one of the biggest custody suites in the county and now takes prisoners from two police divisions. There are 18 cells.

A spokesman for East Sussex County Council said: "The matter is in the hand of our insurers and we will be responding shortly."