The family of a blind teenager with the mental age of a seven-year-old are demanding an inquiry into how he went missing from an Oxford rehabilitation centre.

Ivan McKenzie, 18, sparked a major alert on Saturday when he went missing from the Rivermead centre in Abingdon Road.

The police helicopter was scrambled when a full-scale search of the hospital failed to find him. It was feared Ivan, who is recovering from serious head injuries, could fall into the River Thames, which runs along the east boundary of the centre. But within two minutes the helicopter, using heat-seeking cameras, found Ivan about 150m downstream on the opposite bank, crouching on all fours in a clump of weeds.

Rescuers climbed a fence to reach the stricken teenager, who was airlifted back over the river to the hospital.

A police spokesman said Ivan was "safe and well". But stepdad Richard McLaughlin said the teenager was cold, shivering, frightened and suffering from mild hypothermia.

He demanded an inquiry into the incident and was due to have emergency meetings with staff at the centre.

Mr McLaughlin and his wife Hazel, of the Greenmere estate, Brightwell-cum-

Sotwell, near Wallingford, said Ivan had been at the centre for about a year after treatment at the Radcliffe Infirmary in Oxford. He suffered injuries that left him wheelchair-bound in May 1996 after his bicycle was in a collision with a lorry.

Mr McLaughlin said it was the first weekend they had let Ivan stay in the centre since he was well enough to walk around. They decided to have a break to spend time with their four other children, aged 11, nine, six and two.

They had expressed concerns earlier about supervision after Ivan went missing two months ago.

Mr McLaughlin said: "We are not happy that they let him wander off at will.

"Anything could have happened."

The Nuffield Orthopaedic Centre, which is responsible for the Rivermead, said today that the centre was well staffed when Ivan went missing. A statement added: "All patients at the centre are owed a duty of care, but they are not under any section of the Mental Health Act, and cannot be forcibly restrained or contained.

"All reasonable care was taken within the law, our resources and taking into account the clinical circumstances of the patient."

The centre would be meeting Ivan's parents again on Wednesday to have further discussions about what had happened.

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