Mystery over death of cloned sheep

Australia's first cloned sheep has died unexpectedly, raising concerns that the animal may have suffered a fatal disorder related to the same technique used to create Dolly, the world's first adult clone.

Matilda died last week and a post-mortem examination over the weekend failed to find the cause of death, said Rob Lewis, who heads the South Australian Research Institute near Adelaide.

The cremation of her carcass has been criticised by opponents who argue that there will be no further opportunity to see whether she had suffered any problems directly connected to her being cloned. Matilda was born in April 2000 and had been dead for about a day before her carcass was discovered. "There was nothing grossly obvious in the organs and outer body. The body's been cremated because it was in a very bad state," Dr Lewis said.

One of the concerns about cloning is that it increases the risk of genetic and other congenital abnormalities.