Daniel Heard disappeared from the Cedars Unit last Tuesday

Daniel Heard, 26, disappeared from the Cedars Unit at Wonford House Hospital in Exeter last Tuesday and his body was found by the River Culm on Sunday.

His death has raised new questions over security arrangements at the unit.

The Devon Partnership NHS Trust has launched an internal investigation, but Tiverton and Honiton MP Angela Browning said it needed to be very thorough.

In June 2002, three patients from the unit fell to their deaths from cliffs near Sidmouth.

Then last year a patient was found hanged in the grounds of the unit after going missing.

Daniel Heard showed the first signs of schizophrenia at 17

Mrs Browning said: "Coming on top of other cases in recent months, an overview needs to be taken to see if they have got the right procedures and equipment in place to ensure the safety of patients who are clearly at risk.

"In the past the unit has been very transparent about wanting to share information and identify weaknesses in the system and put them right.

"There is no doubt about their motivation to try and improve the situation at the moment.

"I just think there is a need to look again to try and do everything they can to eliminate these type of cases.

"They are complex. The fact that Daniel was being checked every 15 minutes shows they knew he was someone at risk of harming himself.

The Cedars Unit said it followed the missing persons' procedure

"But we need to look at every angle here to make sure, in the future, these sort of incidents don't happen because we are talking about the end of a person's life."

Mr Heard was 17 when he showed the first signs of the schizophrenia that was to blight his final eight years.

His mother, Linda Kelly, said he was desperate to leave the Cedars Unit because he hated the loss of his independence.

She said he should have been offered more than simply medication to cope with his illness.

"He was forced to take the drugs but never persuaded in any way to have any kind of psychotherapy or counselling," she said.

"I don't think it was offered and I think it may have helped him come to terms with it."

Quickly noticed

Some members of Mr Heard's family are angry that a patient who was the subject of a Section 3 Mental Health Order could be allowed to escape.

But, in a statement, the Devon Partnership NHS Trust said it was noticed very quickly that he had gone and staff immediately followed the missing persons' procedure, which included a local search and contacting the family and police.

In regards to Mr Heard's treatment, the doctors said that because he was so ill, medication was more important than psychotherapy.

Dr Paul Cawthorn, of the Trust, said: "People who are in-patients on the wards do have a key worker and identified nurse who works with them and specifically talks and thinks with them, mainly about day-to-day activities and anything particular that is troubling them.