LONDON: One of the heirs to the multibillion-pound Tetra Pak empire is being treated at a hospital as police wait to interview him in connection with the death of his wife.

Hans Kristian Rausing was arrested on Monday after officers discovered the body of his 48-year-old wife, Eva, at their home in Belgravia, west London.

Rausing — who was initially arrested in south London on suspicion of possession of drugs — was transferred to a hospital from police custody on Tuesday.

Scotland Yard said there was a police presence at the hospital, but it is understood that Rausing has yet to be interviewed over the death of his wife.

Her death is being treated as “unexplained” and is being investigated by the homicide and serious crime command of the London Metropolitan police.

A postmortem at Westminster mortuary in London on Tuesday failed to establish the cause of Mrs Rausing’s death. Further toxicology tests are being carried out to establish how she died.

The couple, who have four teenage children, have struggled for many years with drug addiction, narrowly escaping prison in 2008 after heroin and 2,000 pounds worth of crack cocaine were found at their home. Mrs Rausing had been arrested after trying to smuggle several wraps of cocaine into a reception at the American embassy in Grosvenor Square.

As part of their caution, the couple were required to attend a four-month drug rehabilitation programme, and they were prominent benefactors of a number of anti-drugs charities, even while they continued to struggle with their own addictions.

The American-born Mrs Rausing, the daughter of a wealthy Pepsi executive, met her husband in the 1980s when they were both being treated at a US drug rehabilitation centre.

In a statement following her arrest in 2008, she said: “I have made a serious mistake which I very much regret. I intend to leave as soon as possible to seek the help that I very much need. I have made a grave error and I consider myself to have taken a wrong turn in the course of my life. I am very sorry for the upset I have caused. I thank my family and friends for their kindness and understanding.” After the hearing, the Rausing family said they “hope[d] with all their hearts” that the couple could “overcome their addiction”, and that they would support them.

But the decision to drop charges in favour of a conditional caution attracted some criticism of double standards for wealthy offenders, and was described as “very surprising” by the then Metropolitan police commissioner, Sir Ian Blair, who said it “sends entirely the wrong message about drug use and disregards the harm it does to communities”. He added that the decision not to prosecute “reminds me of the 19th-century legal comment often attributed to Sir James Mathew: ‘In England justice is open to all — just like the Ritz.'”

Though he was born into relatively modest middle-class circumstances in Sweden, Hans Kristian Rausing's life was transformed by the vast wealth generated by his grandfather's packaging invention, which permitted milk to be kept fresh without the need for refrigeration.

His father, Hans Rausing Sr, moved the family to Britain in the 1980s to avoid Sweden's higher tax regime, and in 1996 sold his half of the Tetra Pak company to his now late brother Gad for almost 5 billion pounds. The company is now controlled by Gad Rausing's three children, Jorn, Finn and Kirsten, who are based in Sweden. Hans Rausing Sr, now in his 80s, lives in East Sussex, England, and is thought to have a personal fortune worth almost 6 billion pounds.

Hans Kristian Rausing has two sisters, the older of whom, Lisbet, studied at Berkeley and Harvard and went on to be a research fellow at Imperial College. Sigrid Rausing, his other sister, owns the literary magazine Granta and the publishing firm Portobello books, and is a noted philanthropist.

In an interview in 2004, she said great wealth was something that was not always easy to come to terms with: “Be open about it and be active with it.”

She has said that her philanthropic habit developed partly from guilt, “but I think it was probably shame, if I can make that distinction. People knew you had money, so you could never say: ‘Come back next month.'”

Eva and Hans Kristian Rausing were also philanthropists, supporting, among others, charities working in the arts, sport and addiction. She was even a patron of one charity, the Mentor Foundation, which worked to help people out of addiction and also boasts the Queen of Sweden, Queen Noor of Jordan and Prince Talal bin Abdul-Aziz Al Saud of Saudi Arabia as honorary trustees.

Prince Charles, with whom Hans Kristian Rausing is said to be on first-name terms, has described him as “a very special philanthropist” because of his support for drugs charities.

By arrangement with the Guardian