They did not raise the alarm until three hours after tragic Anne Marie Dooher had left the secure unit in Falkirk Royal Infirmary on June 25 last year and did not call in the police until 6 p.m. that night, another three hours later.

She was found the next morning in her Falkirk home - dead from an overdose of pills.

The blunders were exposed at a fatal accident inquiry into the death of the 53-year-old in Falkirk Sheriff Court this week.

Miss Dooher, of Glynwed Court in Falkirk, had been sectioned under the Mental Health Act after two previous suicide attempts and detained in the strictly controlled ward under a Compulsory Treatment Order (CTO).

She was only supposed to be off the ward for half an hour at a time.

But the inquiry heard the former British Airways stewardess, who had been battling depression for 20 years and been assessed as being of "high risk of self harm", had left the ward before 11 a.m. that day and never reappeared.

Sheriff Craig Caldwell was told nurses should have started the missing persons procedures at 11.30 a.m., a search of the grounds should have been launched immediately and next of kin and police called.

Absence

Michael Stewart, representing NHS Forth Valley, said an investigation had found there were "clear failings in communication between staff".

Deputy charge nurse Carole Anne Wallace said Anne Marie's absence had not immediately caused concern.

She said: "Anne Marie did tend to leave the ward without telling staff. She had a history of exceeding her time off the ward."

Mrs Wallace said a student nurse tried her mobile phone and left a message on her voicemail when she didn't answer.

It was then agreed to give her "leeway as she had always come back."

Mrs Wallace admitted: "The missing person's procedure should have been initiated right away, but on that day communication had fundamentally broken down to the extent the staff didn't know who was dealing with what."

Miss Dooher's sister Rosemary Dean claimed: "Anne Marie went from being a beautiful and successful career woman with her own house and wide circle of friends to being ill, vulnerable and needy.

''That's what her illness did to her and the hospital let her down."

The inquiry was adjourned for further medical evidence.

Sheriff Craig Caldwell will give his findings in writing at a later date.