The number of cases of CJD caused by eating BSE-infected beef may be higher than previously thought.

Scientists at the Institute of Neurology in London have found evidence BSE, in addition to causing so-called variant CJD (vCJD), may also be responsible for some cases of "sporadic" CJD.

So far, 117 people in Britain have died from the incurable brain disease variant vCJD.

Previously, the cause of cases of sporadic CJD - a different strain of the disease - was not known.

The strain, which has been identified for many years, tends to affect older people and a link with eating infected beef had never been made.

Now, however, researchers say some cases of sporadic CJD may have been caused by people eating BSE-infected beef in the late 80s and early 90s.

Urgent study

Professor John Collinge, who led the research on mice at University College, London, told the Guardian newspaper: "When you counsel those who have the classical sporadic disease, you tell them this is not related to what you read in the newspapers, it arises spontaneously out of the blue.

"I guess we can no longer say that."

The researchers want a national study to be carried out urgently to assess the true scale of CJD infection.

The Government says the new findings are potentially important and insists its expert committee will be examining them closely.

It may force the Department of Health to reconsider the size of its compensation scheme for families affected by BSE.

Money is not currently available for sporadic CJD victims or relatives.