ITV News understands that Hans Rausing, one of the richest men in Britain and heir to the Tetra Pak drinks carton empire, has been arrested in connection with his wife's death after her body was found at their home in Chelsea in west London.
Her death was being treated as unexplained.
On Monday morning, Mr Rausing had been detained by police on suspicion of possessing drugs. That afternoon, following a search of their home, Eva Rausing's body was found.
In a statement, the Metropolitan Police have said:
Eva Rausing was born in 1964 and she is the daughter of millionaire American businessman Tom Kemeny, a former Pepsi executive. She was married to Hans Rausing, heir to the £5.4 billion business enterprise built by his Swedish father.
Tetra Pak is one of the world's leading companies for food processing and packaging solutions - delivering services to people in more than 170 countries.
In 2008, Mrs Rausing accepted a caution after she was arrested for being found with about 10g of crack cocaine when she tried to enter the US Embassy in London.
In recent years she had been actively involved in charity work, with her family reportedly donating more than £150 million in the past few years.
Both families have paid tribute to Eva Rausing.