A woman whose adoptive son died of head injuries denied ever hitting him, a court heard.

In an interview with police, Michelle McWilliam said she did nothing to cause the injuries that led to John Smith's death.

Asked if anyone else hurt the four-year-old, she replied: "Everyone loved John. He was a very nice little boy."

She was asked if her husband, Simon, could have been responsible. She replied: "He is my husband. I love him and I trust him. I don't believe my husband is capable of anything."

The couple, of Gardner Road, Fishersgate, Southwick, deny cruelty and insist John was a self-harmer.

Mr McWilliam, in a separate interview, said he had no idea how the boy's fatal injuries were caused.

He said in an interview: "All we know is that John banged himself around a lot.

"He told Michelle he had thrown himself out of bed and banged himself on a radiator."

He said John would poke his face and arms, adding: "John hurt himself at times so often, it is hard to think that he did this on this day and that on that day."

Mrs McWilliam, in her video interview, played at Lewes Crown Court yesterday, told how she found John lifeless in bed on the morning before his death on Christmas Eve 1999.

She said she tried to wake him, shouting at him, slapping his face and shaking him by the shoulder.

But John, still cuddling his favourite dinosaur soft toy, gave no response.

Mrs McWilliam said she ran downstairs and telephoned for an ambulance and John was taken to the Royal Sussex County Hospital, Brighton.

Dr Geoffrey Bryant, accident and emergency consultant at the hospital, said he studied a CT scan of the boy and came to the conclusion the injuries were "highly suggestive and consistent with a non-accidental injury".

He said he was asked how the boy's injuries had been caused and Dr Bryant said by blows to the head.

McWilliam, he said, became angry and blamed social services.

The McWilliams claim they repeatedly told social services about John injuring himself but they had not received any help to deal with the problem.

The court has been told the boy had 54 external injuries and four adult bite marks on his body.

He died from a brain haemorrhage.

The trial continues.