The woman in a cruelty trial took the stand for the first time to deny she either hit or threatened her adoptive son.

Michelle McWilliam said four-year-old John Smith never lived in fear but he self-abused, throwing himself down stairs and into furniture.

She told Lewes Crown Court yesterday: "He was a very happy boy most of the time but there were times when he was anxious."

The anxiety came before and after visits by his former foster carers or natural parents and grandfather, she said.

John made himself sick for three days before and three days after one visit, she said, because he was confused and disturbed.

John had 54 bruises and three adult bite marks on his body when he died but McWilliam and her husband Simon, of Gardner Road, Fishersgate, Southwick, deny cruelty.

Michelle McWilliam said one mark on the boy's face was caused by a carpet burn. Bruises round his ear and neck were inflicted by John pinching himself, she said.

She said she was shocked when she saw them, saying: "I could not believe a small child could do such a thing.

"I told him not to be silly and I gave him a cuddle."

She was shown a photograph of John with bruises on his faces, taken when he was at school. Mrs McWilliam could not explain the wounds and she did not know how they had occurred.

Stephen Kay, for Michelle McWilliam, asked: "Had you been mistreating him, hitting or punching him?"

She replied: "No, not at all."

Mr Kay later asked: "Had you been threatening him to make him give false accounts and making him live in fear?"

She said: "No. He did not live in fear."

She insisted John punched himself in the face and said: "He quite often had bruises on his face."

She was asked about injuries to other parts of his body but she could not account for them.

She didn't like to ask him about them, she said.

She said whenever she did ask John he "stuttered and said, 'I don't know'."

The trial continues.