The thought of climbing into the depths of the dark, cold basement of an imposing classical building would send a shiver down anyone's spine.

But this weekend crowds will flock to Brighton Town Hall eager to experience a set of old police cells, which are believed to be haunted.

After descending a steep staircase, they will see with the spot where a local policeman was murdered when a criminal tried to escape.

Danny Lawrence, who shows visitors around the cells, said: "Visitors are fascinated with history of the old cells.

"During the 1800s a man was caught stealing a carpet in St James's Street and put in the cells. At one point he jumped up, grabbed a heavy iron poker from the fireplace, which is still in the basement, and whacked an officer over the head, killing him."

The criminal was hanged in Horsham for the murder of Chief Constable Henry Soloman in 1844.

The policeman is rumoured to still haunt the cells.

George Vane, who has worked at Brighton Town Hall for more than 20 years, said: "Danny and I have both felt a presence in the basement.

"All the hairs went up on the back of my neck a couple of times.

"Sometimes I have to go down there in the middle of the night but it doesn't bother me. There is not a bad feeling and nothing has ever been thrown about."

The cells themselves have heavy wooden doors with spy holes so the officers could keep watch on the prisoners.

Facilities were basic and there was a public cell, the floor covered only with straw, for drunks to dry out.

Other atmospheric reminders of times gone by include a wash area where prisoners had to bathe in cold water.

If visitors look closely they are able to spot the names of prisoners scratched in the walls.

As well as Henry Soloman's ghost walking the narrow corridors of the cells, another spirit is rumoured to haunt the building, which was built on the site of an old monastery.

A monk had been exiled from the monastery for a misdemeanour and is said to have returned to ask for forgiveness.

Yet he became trapped in a huge fire that ripped through the building and lost his life.

Another hint of the former history of the site, before the town hall was built in 1830, is an old well in the floor of the basement. It still has water running through it.

Visitors will be able to explore the old police cells at Brighton Town Hall on Saturday at 10am, 10.30am, 11am and noon.

The attraction is one of more than 20 unusual and historic buildings taking part in an Open Door event, organised by the Regency Town House charity, this weekend.

Last year's Open Door event, the first of its kind in the city, attracted thousands of visitors.

Organisers hope this year's will be even bigger and better.

Many of the tours, including the police cells, must be booked in advance.

To book a tour of the old police cells or for details of the Open Door 2001 event call 01273 206306.

For a full list of participating buildings, go to www.rth.org.uk