Detective Inspector Sharon Marman testified at an inquest into Eva Rausing's death in Westminster Coroner's Court, The Daily Telegraph reported. Her body was found Monday in the couple's house in the Belgravia neighborhood after her husband was detained by police for driving erratically.
Rausing was hospitalized Tuesday.
"We have not yet been in a position to interview Mr. Rausing," Marman said. "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 inquest was adjourned, pending the results of toxicology tests. A medical examiner was unable to find a cause of death from the autopsy.
Hans Kristian Rausing, 49, one of the richest men in Britain, is a member of the Swedish family that controls the Tetra Pak food processing conglomerate. He and his wife, the daughter of a Pepsi Cola executive, met in a drug rehab clinic.
Marman testified that a small quantity of drugs was found in Hans Kristian Rausing's car. He was reportedly being treated at a South London hospital for alcohol withdrawal.