A four-year-old boy threw himself downstairs and crashed into furniture because he was frightened of being moved to another house, a court heard today.

Simon McWilliam, who is accused of cruelty to the boy, said John Smith was confused and did not know what "mummy and daddy" really meant.

McWilliam said John had good reason for his confusion - he had his birth parents, then he was taken away and fostered by another couple and then he was placed with him and his wife Michelle.

McWilliam said: "He did not know whether there would be a mummy and daddy number four or number five. He did not understand."

McWilliam said that John told him he wished he had one mummy and daddy, like his friends.

McWilliam said that was the reason John harmed himself. McWilliam said he did smack the boy a half dozen times but only lightly and he did not hurt John.

Cross examined by Camden Pratt, prosecuting at Lewes Crown Court, McWilliam denied John was frightened of him and his temper.

John died on Christmas Eve 1999 of a brain haemorrhage.

He had 54 bruises and three adult bite marks on his body.

The McWilliams, of Gardner Road, Fishersgate, Southwick, deny cruelty.

The trial continues.