A woman in Nebraska who was mistaken for dead at a nursing home and later found to be alive at a funeral home has now really died, authorities have confirmed.

Constance Glantz, 74, was declared dead at a nursing home near the state capital of Lincoln on Monday.

Staff at a local funeral home that she was then brought to noticed about two hours later that she was still breathing. They quickly performed CPR on her.

Ms Glantz was quickly taken to hospital, but officials said that she was later declared dead - for a second time - soon after.

Police are now investigating the incident, but they said there is no evidence of criminal intent by the nursing home.

"This is a very unusual case," Chief Deputy Ben Houchin from the Lancaster County Sheriff's Office said at a press briefing on Monday.

"Been doing this 31 years, and nothing like this has ever gotten to this point before."

A coroner was not sent to the nursing home after it declared her dead because Ms Glantz had been placed in hospice care, and the circumstances did not fall within a coroner's remit, Mr Houchin told reporters.

Ms Glantz's death had been anticipated, he explained.

Additionally, "a physician had seen her in the last seven days, and the physician was willing to sign the death certificate, and... there was nothing suspicious at the time of the death".

On Tuesday at around 16:00 local time she was pronounced dead for a second time, Mr Houchin later told reporters.

He added that a post-mortem examination had been scheduled later on Tuesday, and that results could take up to 12 weeks.

“The funeral home did absolutely nothing wrong,” Mr Houchin added. “They are the ones who found that she was still alive.”

Mr Houchin did not name the homes at the centre of the mishap, but the BBC has requested comment from a nursing home named by local media.

The BBC also contacted the funeral parlour named in local media - Butherus, Maser and Love Funeral Home - which said in a statement: “We are proud that our directors and staff handled the recent incident in the news appropriately and with upmost care.”

Ms Glantz is not the only person to be pronounced dead only to reveal themselves as still being alive.

In June last year, 76-year-old Bella Montoya in Ecuador was declared dead following a suspected stroke, placed in a coffin and taken to a funeral parlour for a vigil ahead of her burial. Five hours later, she was found to be alive after the coffin was opened to change her clothes. She did, however, die days later.

In 2018, a South African woman who was initially declared dead following a road accident was discovered alive in a mortuary fridge.

Dr Stephen Hughes, a senior lecturer in medicine at Anglia Ruskin University's School of Medicine in Chelmsford, has said that such cases are rare, but that "death is a process".

"Sometimes somebody may look like they're dead but they're not quite dead," Dr Hughes told the BBC after the incident in Ecuador. "Careful examination is necessary."

Dr Hughes added that doctors would often look for heart sounds or breathing effort for at least a minute before declaring someone dead, and that some drugs could also slow down body processes, giving someone the false appearance of having passed away.