Al Jazeera has previously featured videos of Bin Laden

The news agency said the video was passed to one of its journalists by a Pakistani intelligence official.

The 40-minute tape arrived in Britain on an encrypted CD-Rom decoded by the agency last week, The Sunday Times also reports.

But the high profile Arab television channel Al Jazeera, which has broadcast statements and previous video footage depicting Bin Laden, dismissed the tape as older than reported.

In a statement company officials claim suggestions the video was taped in March are incorrect and that it had 'exclusive' footage of the tape before the end of last year.

Encrypted messages

The time of recording is significant because it may give an indication to officials of when Bin Laden - accused of masterminding the 11 September attacks on the US - was last seen alive.

His whereabouts remain a mystery to the allied forces hunting him and his al-Qaeda party members.

But security experts will still scour the tape's contents, not only for what is said, but for possible encrypted messages to Bin Laden supporters.

A Foreign Office spokesman said: "We are always aware that there is a general threat against western interests.

"This video does not increase it but, of course, we shall continue to remain vigilant.

"We will obviously be examining it."