The building has been sealed off and officials from the International Criminal Tribunal for Former Yugoslavia in the Hague have made a preliminary investigation. They say they believe that ethnic cleansing in Kosovo was co-ordinated from the building.

A police station in Pristina is believed to have been turned into a torture chamber by Serbs

The discovery came as the UK Foreign Office said at least 10,000 people were thought to have been killed in more than 100 separate massacres in Kosovo.

British paratroops found an array of knives and clubs, knuckledusters, mines, pornography and drugs in the police station.

A resident of the predominately-Albanian neighbourhood surrounding the police headquarters said he was beaten and questioned in the concrete-block building, and had seen men and women beaten unconscious in its cells.

Ben Brown in Pristina: Torture was carried out with a bewildering array of instruments

Riza Krasniqi said police beat him with bedposts after seizing him at his nearby home.

During the six hours he was held, he said he saw Albanian men and women from about 15 to 70 years old being beaten.

Elsewhere, new evidence of mass killings has come to light in several places on the ground in Kosovo, as units of the Nato-led international security force (K-For) reach further into the province.

The BBC's Angus Stickler has visited a site close to the town of Djakovica where, just over a month ago, refugees reported seeing 200 bodies in a field.

He found the partially decomposed bodies of three or four people lying in a ditch. In a field, he saw three large mounds which are said to cover the bodies of many more.

Evidence has been taken from the police HQ which is now under guard

The area was strewn with bones and, in the ashes of nearby fires, lay scattered the remnants of passports and personal belongings.

Within the past few days Nato-led peacekeeping forces entering Kosovo have also discovered the sites of what they believe to be atrocities, including mass graves at Kacanik in the south of the province and at Mitrovica in the north.

And the remains of 26 people, reportedly massacred by Serb forces about six weeks ago, have been discovered in Caraluk, about 30km from Pristina.

UK Foreign Office Minister Geoff Hoon said first-hand evidence, combined with the accounts of refugees, indicated at least 10,000 people had been killed in more than 100 massacres in Kosovo.