The family of an autistic man eaten alive by a rodent in a specialist care home have rubbished its claim that the animal was only a mouse.

Jason Ketley, 42, was ‘attacked’ by the animal while at St Ebba’s care centre in Hook Road, Epsom where he has lived for the last 15 years.

Mr Ketley, who is autistic and bi-polar with a mental age of a two year old, was left badly shaken by the incident in November last year and frightened to return to his room.

His mother, Pat Boardman, 64, who lives in Bognor Regis, said: "He was heavily sedated at the time of the incident. He was wandering about in the corridor and staff saw him and as he walked out the rat was still hanging on his neck. And that’s when they took his pyjama top off because it was all bleeding and he had big sores and bite marks all over his back. You could see the length of the teeth."

Staff removed the animal from Mr Ketley’s back and it was killed immediately.

When Mrs Boardman was told about the incident the next day, she said a member of staff described the rodent as "longish, black with a big long tail."

Mrs Boardman has since made an official complaint to the Surrey and Borders Partnership NHS Foundation Trust (SBPFT) who run the centre which specialises in child and adolescent mental health services. The hospital has since launched an investigation but claims it was a ‘mouse’ which attacked Mr Ketley - a claim his mother find’s ludicrous.

She said. "It was not a mouse. A mouse would not have been able to bite like that."

He husband, and Jason’s stepfather, Tom Boardman added: "This field mouse business is ridiculous because mice are herbivores and rats are omnivores. They keep insisting it was a mouse but it wasn’t."

Mrs Boardman was told her son was "beside himself" after the incident, made worse by his inability to communicate his feelings. She said: "Although he was heavily sedated he was holding on to their arms for dear life. He was frightened and he didn’t want to go back in the room. If he can’t explain how he feels how do we know? He could have been having nightmares."

The couple also described having seen a rat outside the front door of the care home about a year before the incident and had alerted staff at the time. Mr Boardman said: "We had just got into the car to leave and I saw something move out the corner of my eye near the front door of the building. There was a rat running between the flower pots which must have been a good 12 inches long. My wife phoned to tell them, so we know they are there."

However SBPFT have insisted they do not have a rat problem and that this was a "one-off" incident.

Jo Young, director quality and nursing at SBPFT said: "The events described here are genuinely shocking and I would like to reassure Mrs Boardman that we are taking her concerns extremely seriously. This is why we have logged the events as a serious incident and are conducting a detailed investigation."

She added: "Our records indicate that a mouse was seen in the house in November and that pest control was alerted immediately but we are unable to provide a complete response to all the concerns raised until we know the outcome of our investigation. I would like to stress that the reported incidents are extremely unusual and that we took urgent action to ensure the safety of people using services on the site. We have maintained contact with the family since the incidents were reported and are disappointed that they felt unable to resolve their concerns through our complaints process alone. We take our responsibility for caring for vulnerable people very seriously and we will act on any findings from our investigation to ensure our high standards of care and support are maintained."