The cause of Amy Winehouse's death could be known in about four weeks, as officials have said that's when results of the toxicology tests are expected to return.

Winehouse, 27, was found dead at her Camden home in London on Saturday. Her death is still a mystery, as medical examiners in London were unable to determine what killed the British singer.

An autopsy on Monday at the St. Pancras Mortuary, failed to determine the cause of death, which is still being classified as "unexplained." Authorities are now waiting for toxicology results, which could take about four weeks.

Coroner Sharon Duff said an investigation will be launched on Oct. 26 to find out what killed the Grammy Award winner on July 23.

Duff released a statement noting that "a section 20 post mortem has been carried out and a histology and toxicology taken to determine the cause of death. The scene was investigated by police and determined non-suspicious."

A section 20 post-mortem indicates that "there is reasonable cause to suspect that a person has died a violent or unnatural death or in any other way which would require an inquest," according to The Hollywood Reporter's article.

The article further stated that such a post-mortem also suggests that authorities have the intention of inquiring further the circumstances leading to Winehouse's death.

The Winehouse family held a private funeral service for the British singer on Tuesday where only close friends and family were invited. She was cremated after a traditonal Jewish funeral service.

There are reports that Winehouse died from a drug and alcohol binge. She had a promising future, and made it big with her 2006 album Back to Black. Winehouse is probably best known for the song "Rehab." But she was never able to kick her drug and alcoholic demons, which she has battled for years.

Winehouse came close to death in 2009 when she and her ex-husband Blake Fielder-Civil went on a three-day drug binge. Fielder-Civil is currently serving a 32-month long sentence in prison for burglary and possession of an imitation firearm. They divorced that year after two years of marriage.

This is Coroner Sharon Duff's statement as reported by The Hollywood Reporter:

"I bring before you the death of Amy Jade Winehouse aged 27, born on the 14th of September 1983 in London. She was a divorced woman living in Camden Square NW1. She was certified dead at her home by a paramedic and a doctor on July 23rd. She was a singer songwriter at the time of her death and was identified by her family here at St Pancras this morning. A section 20 post mortem has been carried out and a histology and toxicology taken to determine the cause of death. The scene was investigated by police and determined non-suspicious."

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