Police pulled a “vulnerable” man from rail tracks at Perth after he went missing from hospital for the seventh time in less than 12 months.
Officers discovered the man scrambling across the train line near the Fair City’s Dundee Road and dragged him to safety.
Control room staff called Network Rail officials to halt trains on the line, but officers rescued him before this could take effect.
It is understood the man is being treated on the Faskally ward at the hospital, which houses “mentally disordered offenders”.
NHS Tayside declined to reveal the nature of any offences but said they took patient safety “very seriously”.
Politicians called for security arrangements regarding the 36-year-old to be revised.
Local MP Pete Wishart said: “This is a very worrying development when we now find that (he) is a threat to others as well as a danger to himself.
“Everything must be done to ensure that no-one is at risk from this man and that his security situation is resolved.”
Mid-Scotland and Fife MSP Murdo Fraser said: “It is important that an appropriate level of care and supervision is provided for those with mental illnesses in Murray Royal.
“Given the number of occasions on which this patient has gone missing, there is clearly a need for his level of supervision to be reviewed.
“Not only is he putting himself at risk, but precious resources are being used every time he disappears.”
Liz Smith MSP, who also represents the area, added: “This is clearly a very vulnerable patient who is in need of specialist care.
“The fact that he has managed to break free into the community on seven different occasions is a matter of concern, not least because of the involvement of the emergency services on two occasions.
“On the last occasion, I asked the chief executive of NHS Tayside, Gerry Marr, to investigate this matter and whilst respecting the confidentiality of individual patient care, I think there are serious questions to be answered in this case.
“NHS Tayside needs to fully explain why security has been so weak. I will be asking NHS Tayside to take action to ensure there is no repeat of these incidents.”
A spokeswoman for NHS Tayside said: “Due to patient confidentiality, we cannot discuss matters relating to an individual patient.
“NHS Tayside has a policy in place which has procedures for staff to follow in the case of a missing patient and these were followed in this instance.
“We take the safety of our patients very seriously and we will be conducting a review into the circumstances surrounding this instance.”
The latest incident involving the patient occurred on Saturday when he was reported missing at around 1.45pm.
He first went missing in December last year, sparking a massive search operation involving dozens of emergency services personnel. Then in June the man disappeared twice in as many days.
Another double rescue operation was staged in July when he waded into the River Tay on two separate occasions, 24 hours apart.
More than 30 firefighters, several police officers and an ambulance crew were scrambled to deal with each incident, estimated to have cost “thousands” of pounds.
Most recently he went missing in the early hours of October 8, turning up safe and well several hours later.