Head injuries suffered by a four-year-old boy were consistent with him being shaken rapidly and thrown against a surface, a court heard.

John Smith died from a brain haemorrhage on Christmas Eve, 1999.

Dr Ian Kenny, of the Royal Alexandra Children's Hospital in Brighton, said an examination of the boy's CT scan showed widespread swelling on the outside of the head and bleeding inside on the opposite side.

The signs, he said, were strongly associated with abuse, although he conceded there was never certainty in such cases.

The boy's adoptive parents Simon and Michelle McWilliam, of Gardner Road, Fishersgate, Southwick, claim the injuries were self -inflicted. They deny cruelty.

Cross examined yesterday, Dr Kenny told Lewes Crown Court there was nothing to distinguish injuries caused by falling or being thrown down stairs.

Dr Elizabeth Carter examined Mrs McWilliam after John's death and found bruising on her face, arm, thigh and back.

She said Mrs McWilliam claimed many injuries were caused by John whom, she claimed, was a "monster" who punched and bit her.

But Dr Carter said, as a mother herself, she thought it unlikely a small child could cause such injuries, saying: "You just don't get them . . . you would stop the child . . . not a little soft four-year-old's hand . . . it doesn't make sense."

Dr Carter said bruises on the defendant's arm looked like she had been gripped but Mrs McWilliam wanted to attribute the marks to John.

A video interview with police on Christmas Day was played to the jury.

In it, Mrs McWilliam said John would bang his head on the floor, throw himself against a radiator and fall off a chair.

Sometimes crying, she sat in a chair, wrapped in a blanket, cuddling one of John's furry toys.

She said she heard and saw John hurt himself many times, often in his bedroom and out of sight.

She said it was unfair to keep checking on him and added: "You have to give him some trust."

The trial continues.