A convict on the run from Homerton’s mental health unit had been locked up for attempted murder in 2014, police today admitted.

Cornell Destouches, 25, has been missing for more than a week after fleeing from a minicab in Walthamstow while on escorted leave from the John Howard Centre in Homerton.

Destouches becomes more dangerous the longer he goes without his schizophrenia medication, and police have warned the public to dial 999 immediately if they see him.

In a renewed appeal, Scotland Yard revealed he was detained under a mental health order in July 2014 after pleading guilty to the attempted murder of a Police Community Support Officer (PCSO), who he stabbed in 2013.

Questions have been raised about why Destouches was not tagged.

The centre bowed to pressure last summer and announced it would electronically tag detainees on escorted leave after the third patient went missing in as many months.

Acting Ch Insp Ian Simpkins told the Gazette last week it could have potentially made it easier for the police to trace him had he been tagged, assuming the tag stayed on.

“As I understand it he has now got sufficient capacity to understand the implications of what he is doing so it might have provided a deterrent, knowing that he would have had to remove a tag,” he said.

“No tag will be indestructible forever, if he was committed to remove it, you would need an implement to remove it.”

A “shocked” MP Meg Hillier has asked the John Howard Centre for a full explanation.

“They didn’t tag him and I want to find out from them what’s going on,” she said. “There is a difference between someone getting back late because they missed the bus, but when someone particularly dangerous has run away, that’s intent. The main thing is to get this person back into custody again so the public is safe.”

Destouches was last seen at about 5pm on Sunday, 10 April, when he fled from a minicab at the junction of The Drive and Churchill Road, Walthamstow.

He is described as black, of medium build, 5ft 11inches tall, with braided hair and a black beard.

He was last seen wearing a black and grey T-shirt, blue jacket, blue jeans and navy trainers and was carrying a grey rucksack.

Det Insp Paul Ridley, from Hackney CID, said: “A major investigation is underway to locate Cornell Destouches. I must re-iterate my earlier warning to the public - Destouches is a violent individual who could pose a threat if confronted. If you see him please do not approach or challenge him, but dial 999 immediately.

“All I require is an indication as to this man’s whereabouts and I can assure you it will be immediately acted upon. My primary focus is apprehending Destouches.”

Crimestoppers can be contacted on 0800 555 111.