Manuela Gomez Ruiz, 74, was transferred out of the main trauma room at the Marian Medical Centre in Santa Maria, California, when Jackson was rushed in with "flu-like symptoms" last week.
 
Her family claims she was taken off a machine ventilator and her breathing was instead assisted manually by a hand pump.

Mrs Ruiz was being treated after having a heart attack but suffered two more that day before she died.

Her daughter-in-law, Anna Ruiz, told ABC News she saw Jackson walk into the emergency unit.

"He was walking unassisted," she claimed.
 
Mrs Ruiz’s daughter Maria Elena Ortiz was also in the hospital and objected when her mother was moved.

"Why does she have to be moved if he’s coming in for a stomach flu?" she said.

"I said, 'My mother just had a heart attack and I think it's more critical than a stomach flu'. They didn’t say anything."

The family claims the chaos caused by Jackson's arrival distracted staff. They said equipment had to be crammed into the smaller room and they were limited to two visitors at a time.

Those visitors could not then leave because the hospital restricted movement in the corridors when Jackson arrived, the family claims.

The family have hired a lawyer to sue the hospital and the star.

Jackson’s publicist Raymone Bain issued a statement saying: "Michael Jackson sends his condolences to the family of the deceased.

"However, it is outrageous that Michael Jackson’s name would be invoked into a situation of which he had no authority or control."

Jury selection in Jackson’s child molestation trial was delayed while the singer recovered from the flu.

Opening arguments are scheduled to begin in the Santa Maria court on Monday.