The European Commission has requested further investigations on three unusual cases of Transmissible Spongiform Encephalopathies (TSE) in sheep, saying that it cannot rule out the possibility of BSE.

Tests conducted by an expert panel from the Community Reference Laboratory (CRL) showed that the brains of two sheep from France and one from Cyprus had an unusual molecular profile that warranted further investigation. According to a commission statement, "there is insufficient evidence to definitively rule out BSE".

The two French sheep being tested were born in 2000 and 2002, and died on-farm. The Cypriot sheep, which developed clinical signs of a TSE-linked disease, died at two years old. TSEs belong to a family of diseases characterised by a degeneration of brain tissue - such as Creutzfeldt Jackob Disease in humans, scrapie in sheep and BSE in cows.

The commission is now considering a review of the current TSE monitoring programmes. The next level of testing recommended by the CRL expert panel will use a mouse bioassay test and will take between 12-18 months to complete.

The Commission said that BSE has never been found under natural circumstances in sheep, but the first case of BSE in a goat was confirmed last year. It also said there is no risk to public health, as the sheep did not enter the food and feed chain.

The EU has applied safety measures to all farmed ruminants, including a ban on the use of animal proteins in feedstuffs, the removal of specified risk materials such as brain, spinal cord, part of the intestines from the food and feed chain, the slaughter of sheep and goat herds affected by scrapie, and the application of a TSE surveillance programme.