Police have confirmed that Eva Rausing, one of the richest women in Britain, has been found dead.
A man reported to be her husband Hans, the heir to the Tetra Pak drinks carton empire, who has been arrested over the death, has been moved from a police station to a "medical facility".
He was held over the discovery of his 48-year-old wife's body at their home in Cadogan Place, Chelsea.
The couple at the 2003 Human Rights Watch Annual Dinner
The 49-year-old man who has been held was arrested in south London yesterday morning on suspicion of possession of drugs.
Following a subsequent search that afternoon of an address in Cadogan Place, a body was found.
The man was then further arrested in connection with the death.
A Scotland Yard spokesman said: "A post mortem today at Westminster Mortuary did not establish a formal cause of death and we await the results of further tests.
"The man is no longer at a police station, but is currently receiving medical attention.
"Officers from the Homicide and Serious Crime Command are investigating, and the death continues to be treated at this time as unexplained."
The man is at a "medical facility", he said.
Mr Rausing stands to inherit the £5.4 billion business enterprise built by his Swedish father, also named Hans.
Mr Rausing, then 45, was charged with drugs offences after police found crack cocaine, cocaine and heroin during a search of his home.
After lengthy discussions between his legal team and prosecutors, he accepted a conditional police caution instead.
Neither Mr Rausing nor his wife Eva, who also faced drugs charges, was present at City of Westminster Magistrates' Court that August to hear that the prosecution had ended.
The couple had been arrested in the April after Mrs Rausing was caught with drugs as she tried to enter the US Embassy in London.
Court documents revealed Mrs Rausing, then 44, was carrying about 10g of crack cocaine, 2.5g of heroin and 2.35g of diethylpropion, a banned stimulant and appetite suppressant.
A further drugs stash, 220mg of diazepam, used to treat anxiety, was also found in her Renault Clio car.
The couple's £5 million Georgian five-storey town house in Cadogan Place was subsequently searched.
Officers found 0.2oz (5.63g) of crack cocaine, 0.1oz (2.9g) of heroin and almost 1.8oz (52g) of cocaine.
The conditional cautions, administered by a senior local officer, meant the couple admitted possessing the drugs.
Mr Rausing's parents and siblings said then they were supporting the couple as they fought to overcome drug addiction.
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