Eva Rausing death: police still waiting to interview husband Police investigating at the home of Eva and Hans Kristian Rausing. Photograph: IBL/Rex Features Detectives are still waiting to interview one of the heirs to the Tetra Pak fortune over the death of his wife at their mansion in Belgravia, London. An inquest into the death of Eva Rausing heard on Friday that Hans Kristian Rausing was being treated in hospital for alcohol withdrawal after his arrest on Monday. He has yet to be questioned over the death of his wife, which is being treated as "unexplained." Mrs Rausing's cause of death has yet to be established and further tests are being carried out on the body which has undergone a degree of decomposition due to the length of time it lay in the couple's house before being discovered by police, the Guardian understands. Officers found the body in an upstairs bedroom of the couple's home in Cadogan Place, Belgravia, after Mr Rausing was arrested in Wandsworth for driving erratically. Detectives arrested him again in connection with his wife's death after the discovery of her body. An inquest into the death was opened and adjourned on Friday. Detective Inspector Sharon Marman told Westminster coroners court: "We have not yet been in a position to interview Mr Rausing. He has been arrested on suspicion of her murder and we await notification of when he would be fit to be interviewed by police. The Guardian understands that although the detective used the word "murder," the inquiry has not changed from being an investigation into an "unexplained death." Outlining the facts of the case, Marman said: "On Monday July 9 this year police had the occasion to stop Hans Rausing driving a car in Wandsworth. The officer suspected that the driver was under the influence of drugs or alcohol. As a result he was arrested and his car was searched. Within the car a small amount of drugs were found and he was taken back to Wandsworth police station. An authority was granted to search his home address. During the course of the search officers found the apparently lifeless body of a female in one of the bedrooms. That female has been identified as Eva Louise Rausing. Although the death is being investigated by detectives from the homicide and serious crime command, it is understood nothing has emerged yet to suggest a homicide has taken place. One of the theories being examined is that Mrs Rausing died of a self-administered overdose. The court was told Mrs Rausing's father, Thomas Kemeny, supplied identifying details to the coroner. The deputy coroner, Shirley Radcliffe, will review the case at a private hearing in October. Mr Rausing, whose family is worth an estimated £4.5bn and was ranked as Britain's 12th richest in last year's Sunday Times Rich List, is being represented by 7/7 barrister Neil Saunders QC. A postmortem examination has been carried out by the Home Office pathologist Nat Carey in the presence of the defence pathologist Simon Poole, but no obvious cause of death has been found. Further tests, including toxicology, are pending. Detectives do not know how long Mrs Rausing's body lay in the home but it is understood she may have been dead for up to a week. It is also not established yet whether Mr Rausing was in the house throughout that period. Police have been questioning staff at their home and reviewing CCTV tapes to try to establish when she was last seen alive. The couple's drug addiction has been well-documented over the years and recent photos appeared to show the pair in a fragile state.