Eva Rausing, one of Britain's richest women, has been found dead in a west London home, police say.

The 48-year-old was the American-born wife of Hans Kristian Rausing - heir to the multibillion-dollar Tetra Pak packaging fortune.

London police said on Tuesday officers had found the body on Monday at an address in Cadogan Place in the upmarket Belgravia area of the British capital.

They said the death was being treated as unexplained and the discovery had followed the arrest of a 49-year-old man on suspicion of possessing drugs.

Police confirmed the identity of the deceased in a statement, adding that the man, who had been arrested in connection with the death, was no longer at a police station but receiving medical attention.

They also said an autopsy had not yet established a formal cause of death.

American Rausing and her husband Hans Kristian - whose Swedish father Hans is worth $6.7bn, according to the Sunday Times rich list - have both battled with drug problems in the past, media reports said.

They were arrested in 2008 on suspicion of possessing cocaine and heroin after Eva Rausing was caught reportedly trying to smuggle the drugs into the US embassy in London, but charges were later dropped.

"I have made a grave error and consider myself to have taken a wrong turn in the course of my life," Eva Rausing, whose father is a former Pepsi executive, told media at the time.