Cherry Knowle Hospital, in Ryhope, pictured, has become a magnet for paranormal enthusiasts after it was billed the "most haunted hospital in the UK".

The 19th-century Laurels block at the hospital has featured on websites dedicated to haunted buildings.

The derelict block has been broken into on a number of occasions by bands of urban explorers. Police have also arrested more than 12 people on suspicion of burglary at the premises during the past year.

Officers voiced their concerns for public safety at a recent crime prevention meeting. As well as ghosthunters, it is also being targeted by vandals, yobs and underage drinkers.

Large parts of the red-brick building, which has been empty since it closed in 1998, have been left in a state of disrepair and littered with cans, broken bottles and other waste.

Northumbria Police today warned that it may also contain asbestos and ordered unwanted visitors to stay away.

Neighbourhood Inspector Mark Ord for Hendon, Ryhope and Grangetown said: "We are well aware of this problem and are working with our partners, including the health authority and the local authority to deal with this.

"We have stepped up regular police patrols in this area and the health authority has increased internal security. We have also arrested more than a dozen people on suspicion of burglary at this location over the last 12 months.

"We also want to warn people who persist in breaking into the building that they are putting themselves at considerable risk.

"The property is boarded up and has asbestos inside, the floor is full of holes and we are concerned that those who do force their way in could injure themselves.

"We will continue to work closely with our partners to deal with intruders but would urge people to be sensible and to keep away."

Opened in 1895, the facility comprises six wards on either side of a combined chapel and recreation hall. An isolation hospital and infirmary block were added in 1902.

In the 1930s, an admissions hospital and wartime emergency medical huts were constructed nearby, which became Ryhope General Hospital. The rest of the site became known as Cherry Knowle Hospital when it was acquired by the NHS in 1948.

As community care replaced the long term stay facilities, the original asylum at Cherry Knowle, or Laurels block, eventually closed in the late 1990s while other satellite buildings were retained for use by mental health organisations.

The Department of Health plans to redevelop the site and build a new facility.

A spokesman said: "The site is currently owned by the Department of Health, but part of it is being transferred to English Partnerships.

The remainder of the site is earmarked for health use."