The death of a North-East woman whose body was found in a hospital stairwell in America weeks after going missing was linked to chronic alcohol abuse, a coroner has reported.

Lynne Spalding, 57, disappeared from her room at San Francisco General Hospital on September 21.

The 57-year-old - who moved to the US from Peterlee, County Durham, 23 years ago - was found in the locked stairwell by a member of the hospital's engineering staff during a routine check 17 days after she vanished.

San Francisco assistant medical examiner Ellen Moffat said in a new report that Ms Spalding probably died of a chemical imbalance due to complications from chronic alcohol abuse.

The mother-of-two had been dead for days before being discovered.

The notes add that Ms Spalding was confused and delirious on the day she disappeared, not aware of what day it was or why she was in hospital.

Several employees with the city sheriff's department, which provides hospital security, were reassigned after Sheriff Ross Mirkarimi acknowledged that a thorough search for Ms Spalding was never conducted.

Earlier this year San Francisco mayor Ed Lee announced an independent consultant will investigate the hospital's security and patient safety protocols.

''This should not have happened, we all agree,'' Mr Lee said. ''And we want to prevent it from ever happening again.''

There is a separate police inquiry into Ms Spalding's death and an internal investigation of hospital security measures by San Francisco sheriff's department.

''A thorough independent review is required, and we will do that,'' Mr Lee said. ''The city is responsible for what happened here.''

Ms Spalding's friends and relatives spent days scouring the streets of the Californian city with flyers because they were ''under the assumption that San Francisco General had been searched and Lynne was not here''.

Speaking after her discovery, family spokesman David Perry said Ms Spalding, a marketing and sales expert, had retained her British accent, which was ''thick enough to peel the paint off a ship''.

''She was the very best of England and the United States combined,'' he said.

''Her loss will be felt greatly, not only in her family but across San Francisco because everyone knew Lynne Spalding here.''

Ms Spalding arrived at the hospital thin and frail with her children worried about her condition.

She was admitted for a bladder or urinary tract infection on September 19 and was reported missing from her room two days later.