Detailed tests are being carried out at the EU’s reference laboratory in Weybridge, Surrey, on three sheep brains, to find out whether the animals in question were suffering from BSE.
The sheep, two from France and one from Cyprus, died on farms.
They were submitted for post-mortem testing under the EU’s transmissible spongiform encephalopathy (TSE) monitoring programme.
Initial tests were positive for TSEs and the brain samples were submitted to Weybridge for “second level” testing.
This revealed “unusual molecular profiles” which made it impossible to rule out BSE.
The scientists at Weybridge have now embarked on so-called “mouse bioassay” testing.
This involves inoculating mice with infected tissue from the dead sheep and seeing whether they develop BSE.
The process takes 12-18 months.
“BSE has never been found under natural circumstances in sheep,” said an EU Commission statement.
“But the first case of BSE in a goat was confirmed last year.”
This led to a step increase in the level of surveillance across the EU sheep and goat population.
To date, over 1.4m sheep and 380,000 goats have been tested.
The EU Commission has stressed that the development poses no threat to human health, since the sheep did not enter the human food chain.