Whenever British forces are held against their will, anywhere in the world, it is something the government takes very seriously

Tony Blair

The soldier met the UK hostage negotiation team and was later believed to have rejoined his colleagues, added the spokesman.

Colonel Fordham was accompanied by Major Johnny Paul Koroma, a former coup leader, who is now a member of the Sierra Leonean Government, The Times newspaper reported.

The paper added there were no negotiations, but the rebel leader was given a letter from the Sierra Leonean Government telling him to release the hostages.

UK prime minister Tony Blair is to be briefed on the situation on his return from holiday on Tuesday.

A Downing Street spokesman said Mr Blair realised it was a "complex and difficult situation" but wanted to be updated immediately.

"Whenever British forces are held against their will, anywhere in the world, it is something the government takes very seriously," said Mr Blair.

'Good spirits'

Colonel Stewart Douglas, of the Royal Irish Regiment, told BBC News 24 that the soldiers were being treated well and that none of them had been injured.

He said: "It is an unpleasant situation for them but they are in good spirits.

"It is a strong group and they are experienced soldiers... it won't be the first time they will have found themselves in a conflict environment."

He said the soldiers would have been trained for such a hostage situation and that they would be putting their "procedures into place".

"It depends on their captors but I think it is a good sign that the captors are in direct contact with us," he added.

He said the men's families were receiving regularly updates of the situation.

"The families are our prime concern," he said.

"We have a very well-developed regimental service and we are in a position to give good support to the families."

Local politics

The BBC West Africa correspondent, Mark Doyle, says the West Side Boys are believed to want food and medicine in return for their hostages, but that complex local politics could also be involved.

The meeting has raised hopes of progress towards the hostages' release, he adds.

According to some reports the meeting with Colonel Kallay took place at a UN peacekeeping base at Masiaka.

The 11 members of the Royal Irish Regiment (RIR), were seized together with a soldier from Sierra Leone, outside the capital, Freetown, on Friday.

British forces arrived to bolster the peacekeeping mission

Eight of the soldiers are from Northern Ireland, two from the Republic of Ireland and one from Merseyside.

The West Side Boys swear allegiance to the former military government headed by Mr Koroma, but remain in opposition to the present Sierra Leonean Government despite the fact that Mr Koroma is now a member of it.

They are known for wearing bizarre clothing and being almost perpetually drunk, but they reputedly use their guns without hesitation, and command fear in the areas which they control.

They are not connected to the main rebel group in Sierra Leone, the Revolutionary United Front.

On Monday the UN Secretary-General Kofi Annan said he expected the kidnapped soldiers to be released "in the near future".

The UN is assisting British and Sierra Leonean authorities to negotiate with the captors.