A NORTH-EAST woman found dead in a hospital stairwell in America more than two weeks after going missing was not the victim of an attack, a family spokesman has said.

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

The mother-of-two, who was originally from Peterlee, County Durham, had lived in the US for 23 years.

She was last seen in bed at 10.15am that day by a nurse, and despite a search of the hospital, was not found until 17 days later by a member of engineering staff on a routine check.

Family spokesman David Perry said the coroner had not yet established a cause or time of death but investigators have ruled out foul play.

San Francisco mayor Ed Lee has 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."

Officials said they are investigating how she got on to the outside stairwell, what caused her death and why a search did not locate her sooner.

The hospital and sheriff's department conducted a search of the premises and 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".

"Lynne Spalding died alone, in the stairwell, at one of the finest medical institutions in this country," said Mr Perry.

"I hear that the San Francisco sheriff's department initiated a search. Well, evidently it wasn't a very good one. I think there are a lot of questions to be asked."

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.