The health secretary has told MPs that it may be possible for variant CJD to be passed on through blood transfusions.

In a Commons statement on Wednesday, John Reid revealed that one individual case where possible blood-to-blood transmission may have taken place had come to light.

In 1996 a vCJD positive person donated blood, which was later given to another individual.

At the time, the donor showed no signs of having vCJD, but went on to develop the disease three years later, and died from it in 1999.

The recipient died earlier this year, with examinations appearing to confirm this death was also caused by vCJD.

"In the light of these facts, it is therefore possible that the disease was transmitted from donor to recipient by blood transfusion," a sombre Reid told MPs.

"This is a possibility, not a proven causal connection, because it is also possible that both individuals separately contracted variant CJD."

"This is a single incident...however, the possibility of this being transfusion-related cannot be discounted although it is impossible to be sure exactly what was the route of infection."

He said this was the first report from anywhere in the world of possible transfusion of the disease via blood.

Reid sought to offer reassurance that there was "no way" of presently screening blood but a "range of precautionary measures" had already been put in place.

White blood cells are removed from donated blood in a bid to reduce the possibility of infection, the health secretary said, and UK-sourced plasma had been phased out as "another highly precautionary measure".

He urged the public to remember that no treatment was risk-free and that "so far we have only one single report" of the possible transmission of vCJD through blood donations.

"As for the wider situation...thankfully so far we have not seen the thousands of cases of vCJD that some projections suggested," he said.

"Over the last three years the annual number of new cases has fallen each year.

"However there should be no complacency. It remains premature to conclude that the epidemic has peaked, and in any case, any single case of variant CJD is a tragic one for the patient and family concerned."

The chief medical officer will oversee further investigations on the issue.