British billionaire Hans Kristian Rausing may have lived with his wife Eva's body for up to four days before it was found by police, Daily Mail reported on Thursday.
Despite living in a vast 15-million-pound Belgravia mansion, the couple - who had fought a long battle against drug addiction - had become increasingly reclusive, confining themselves to two squalid rooms, the newspaper said.
Details of the extraordinary lifestyle of one of Britain's richest couples emerged as Scotland Yard continued to probe the "unexplained death" of 48-year-old Rausing.
Investigators now believe the American wife of the 49-year-old heir to the 4.5 billion pounds Tetra Pak drinks carton fortune may have been dead for three or four days in an upstairs bedroom of the house before being discovered by police.
Officers are studying phone, text and email messages to see when she last used them and CCTV security footage to try to discover whether her husband spent time in the house during the period she was dead.
The couple - friends of Prince Charles - have fought a long, painful battle against drug addiction and both were cautioned four years ago by Scotland Yard for drug offences.
They met while in a drug rehabilitation centre in the US and friends say they struggled to beat their addiction.
A post-mortem examination failed to reveal how Rausing died and toxicology and other tests are under way.
It emerged on Wednesday that Hans Rausing was arrested Monday while driving erratically in Wandsworth, South London.
He was found to be in possession of Class A drugs and this led police to search the six-storey house where his wife's body was found.