The group is set to join an international team of forensics experts, working against the clock to discover the way in which thousands of Kosovans met their deaths.

Reporting to the International War Crimes Tribunal, the team is made up of specialists in - amongst other disciplines - explosives, ballistics, fire analysis and dental forensics.

Recovering bodies

Its members from the UK have been drafted from the Metropolitan Police Force's anti-terrorism squad, the Forensic Science Service and various police forces across the country.

Following an initial investigation of sites of mass graves and killings, the team is due to move into the area to begin work in earnest on Friday.

There is concern that vital evidence such as clothing and papers may be wiped out as returning refugees lay their dead to rest.

Scientists will not be able to take their laboratories with them

It is thought that UK involvement in evidence gathering will last somewhere in the region of three weeks.

Their remit, according to Home Office spokesman Eddie Scanlon, is to support the International Criminal Tribunal for Former Yugoslavia in carrying out "forensic examinations and recovering bodies".

War crimes investigation spokesman Paul Risley told journalists on Thursday: "There is clearly a very long list of possible sites of war crimes.

"We would like to be able to check each and every one of these sites."

But he added that the scale of the operation - it is estimated that about 10,000 people have been killed - will probably mean that exhumation of all bodies will be impossible.

He added: "It is likely that we will have to work specifically to our own target to prove the indictments we have already made against Milosevic and his associates."

The remains of what appears to be a torture chamber have already been discovered

"The important thing that we face right now is to gather the scientific evidence of these massacres where they occurred - the clothes, pieces of papers, IDs, that may be lying around the sites of war crimes.

"This is the sort of evidence our investigators must get to at the sites as soon as possible. There is a window that is rapidly closing between now and when K-For secure these sites, and when the refugees begin coming home."

Rob Smith, spokesman for the UK's Forensic Science Service, which operates out of six laboratories nationwide, said: "We have two scientists who are travelling out there. One is a ballistics expert and the other is a fire investigation expert.

"The ballistics expert will be looking at how people have been shot, from what angle, how close the gun was held to them, what type of gun was used.

"The fire expert will be looking at things like, was a fire started deliberately? Was an accelerant like petrol used?

"It is the type of evidence that is presented in coroners courts and criminal courts here in the UK.

"The main difference with what they are doing over there is in the scale of the operation, and the fact that they will be making their reports to the IWCT."

He said that the forensic scientists - who for the time being are not being named by the Home Office - would also have to face up to difficulties including lack of facilities, and accessing remote areas in rural areas.

The experts work in Kosovo will not be greatly different to what they do in the UK

He said: "It may well be that they bring evidence home for analysis. Obviously, you cannot very easily pack up a whole laboratory and take it with you. They will be taking with them their initial kit and evidence recovery packages."

It is not the first time that UK Forensic Services have been called on overseas.

The Forensic Science Society said that some of its members had been called upon to carry out similar duties in Bosnia in the wake of the last Balkan conflict.

And the Forensic Science Service is regularly called upon to help solve crimes in other countries.

Prepared for grim task

One of the most famous in recent years was the case of a Canadian man who had protested his innocence for the whole of his 20-odd years imprisonment for rape.

Mr Smith said: "There just wasn't the evidence available to establish his innocence, but we were able to test clothing taken from the victim, and it turned out that he had been innocent of the attack all along."

He added that scientists due to gather evidence of war crimes are as prepared as possible for their grim task.

"There will be a relay system ready to be put into operation if required," he said.