Detectives are investigating allegations of drug dealing by outsiders walking on to the wing at the Lister Hospital, Stevenage, Hertfordshire, in the days before David Lang's death.
The jury also asked that managers at the hospital, part of the North Herts NHS Trust, look at staffing levels in the unit as they recorded an open verdict on the death of Mr Lang, 35, discovered hanging from a rail by his dressing gown belt.
Mind, the mental health charity which supported Mr Lang's family at the two-day inquest at Hitchin, Hertfordshire, later criticised 'serious deficiencies' in the management of the unit at the hospital where there were six apparent suicides between May and September.
Adina Halpern, the charity's legal officer, also attacked the hospital for its continuing failure to publish three reports into the psychiatric wing, two on the apparent suicides, and another into the unlawful killing of a 70-year-old patient which resulted in the conviction of a nurse for conspiracy to pervert the course of justice.
But a spokeswoman for the hospital, rejected the accusations of secrecy, and said the recommendations in the reports had been made public, with many already in train or under consideration.
In particular, the hospital was about to appoint three extra nurses and a manager for the unit with discussions under way over the creation of three new consultant psychiatrists' posts and further junior posts. Staff and management would be co-operating fully with the police investigation, she said.
However, Lorraine Rowe, Mr Lang's sister, maintained his death was partly due to lax security, which failed to prevent the entry of drug dealers who 'hassled' him for money and supplied the methadone found in his body.
Dr Patrick Toseland, a consultant toxicologist, found levels of the drug which were consistent with a 'maintenance' dose being used to wean Mr Lang off his habit of half a gram of heroin a day.
Only later did he discover that the treatment chosen by Mr Lang, a voluntary patient on the detoxification programme, did not involve methadone, which he would have to have taken orally in 50 milligram doses over the previous four or five days to achieve the levels discovered.
A urine test carried out four days after he entered the unit showed no traces of methadone in his body.
None of the staff who gave evidence at the inquest had any clue that drugs were being supplied, but doctors felt that Mr Lang was making good progress on the medication prescribed even though he had said once that his situation was hopeless.
Nurses found him in a locked bathroom hanging from a 3ft high towel rail, but seated in such a way that he was suspended just off the ground which cut the blood supply to his brain, making him quickly unconscious and causing his death within four or five minutes.Reuse content