Billionaire Tetra Pak heir Hans Kristian Rausing may have lived with the body of his wife Eva for a week

Hans Kristian Rausing may have lived with the body of his wife for more than a week in their £50 million Belgravia home.

The London Evening Standard reported that Eva Rausing is believed to have died at least a week before her body was discovered by police and that investigators were now examining CCTV to establish comings and goings at the couple’s six story mansion in Cadogan Place.

Police are waiting to question Mr Rausing in connection with concealing Eva’s body but the heir to the £4.5 billion TetraPak food packaging fortune, and one of Britain’s richest men, remains in a secure hospital after being admitted for treatment last night.

The body of 48-year-old Eva, a friend of Prince Charles, was discovered in an upstairs bedroom when police went to search the couple’s home after Mr. Rausing was arrested on suspicion of possession of Class A drugs on Monday.

A post-mortem failed to establish a formal cause of death and police await the result of toxicology tests, although it is believed Mrs Rausing died of a drugs overdose.

Although Mr Rausing stands to inherit a multi-billion pound fortune from his 86-year-old father Hans, the couple are reported to have lived in “a twilight world of addiction”.

Mr Rausing was initially stopped for driving erratically in south London on Monday and subsequently arrested on suspicion of possession of Class A drugs.

Scotland Yard confirmed Mr Rausing remained under arrest but said he had been transferred to hospital for treatment. His condition is not thought to be life-threatening and is believed to be related to drugs.

Mrs Rausing is the daughter of wealthy Pepsi executive Tom Kemeny. In 2008 she was arrested after trying to smuggle crack cocaine and heroin into a party at the US Embassy in London.

More drugs were found in her Renault Clio car and at the couple’s home, but prosecutors later dropped charges in favour of conditional cautions.

The Standard reported that the couple were seen walking the streets around their home in May, but neighbours said they were reclusive.

Mr Rausing was often seen wearing a baseball hat and clutching a pack of tobacco. One insider told the Standard: “It appears they lived chaotic lifestyles, people did not hear from them from one week to the next.”