Tests continue to determine the cause of death of US-born Eva Rausing, who was married to TetraPak container heir Hans Kristian Rausing.
Police were initially searching the couples’ home in central London for drugs when they found her body on Monday.
A 49-year-old man, believed to be her husband, has been arrested in connection with her death.
Eva Rausing, 48, daughter of US businessman Tom Kemeny, had led a gilded life marred by drug addiction.
She had a host of connections with royal patrons of anti-drug charities to which she and her husband had donated millions from the fortune his Swedish grandfather made from packaging.
The couple, who were reported to have met while undergoing rehab in the United States, hit headlines in 2008 when Eva Rausing was found carrying heroin and crack cocaine as she entered the US embassy in London. Charges against her and her husband were later dropped.
Her father-in-law, Hans Rausing, 86, is one of the world’s wealthiest men, ranked 88th in the Forbes rich list.