The body of Eva Rausing was found under bed clothes and wrapped in bin bags stuck together with gaffer tape, a court was told on Wednesday.
Millionaire husband Hans Rausing appeared in court charged with preventing her having a lawful and decent burial.
Rausing, who looked frail in the dock at West London Magistrates' Court, was granted conditional bail to appear again at Isleworth Crown Court on 26 July.
Police discovered the decomposing body of mother-of-four Mrs Rausing after they arrested her husband - the heir to the Tetra Pak millions - on suspicion of driving under the influence of alcohol or drugs last Monday.
Trial: Hans Rausing, left, is accused over the treatment of his dead wife, Eva, right
According to The Evening Standard, prosecuting lawyer Brinkman May told the court: "On the floor next to the bed they [the police] found a large quantity of bedding, with bin bags stuck together with gaffer tape. It was several feet deep. Her body was in an advanced state of decomposition."
Mrs Rausing, one of Britain's richest women, was found in an annexe on the second floor of the opulent Cadogan Place house in London's Chelsea which she shared with her 49-year-old husband.
Bearded and bespectacled, Rausing spoke only to confirm his name, age and address in court on Wednesday.
Rausing, whose family made a fortune when they sold the Tetra Pak business in the 1990s, was wearing a dark suit and light blue shirt with no tie.
District Judge James Henderson told him: "I grant you bail on two conditions. The first is that you must reside at the Capio Nightingale Hospital and that you live there and sleep there overnight, and you do not leave that hospital unless you are accompanied by a member of hospital staff."
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