LONDON – When Eva Rausing approached the heavily guarded U.S. Embassy in London’s Grosvenor Square four years ago to deal with a routine passport matter, she had to pass through British security, then face an airport-style metal detector so she and her handbag could be scanned for weapons and contraband.

The wealthy American didn’t leave her stash at home. She tried to pass the security scan with small amounts of crack cocaine, heroin and a banned stimulant in her purse.

The subsequent arrest led police to search the multimillion-dollar property she shared with her husband, Tetra Pak heir Hans Kristian Rausing. Police found still more drugs, including a sizeable amount of cocaine.

Charges were dropped in exchange for a formal police warning, but the arrest made public what close family and friends already knew: The golden couple, with untold riches, were deeply mired in drug addiction even as they gave millions to numerous anti-addiction charities.

Their sad tale reached its climax this week when 48-year-old Eva Rausing was found dead in their home, and her husband was detained for questioning about drug use and placed in hospital care. The cause of Eva Rausing’s death has not yet been established.

Drugs can be a scourge for the poor, the middle class and even the super-rich — those who, like the Rausings, measure their net worth in the billions.

“Addiction doesn’t know any class boundaries,” said Amanda Thomson, spokeswoman for Action on Addiction, one of many charities that the Rausings supported even as they swooned toward drugged-out oblivion.

Eva Rausing was born into a wealthy American family headed by former Pepsi executive Tom Kemeny, and her husband was an heir to the formidable Tetra Pak fortune — his father and his family have a spot on Britain’s “Rich List” with a net worth estimated at 4.3 billion pounds ($6.7 billion).

The money came from his family’s development of a better milk carton – one that could be packed and shipped like bricks, easing the distribution of milk and juices throughout the world.

The Rausings married shortly after they met in the 1980s and raised four children from their London base in an exclusive section of the Chelsea neighborhood.

Before the embassy arrest, Eva Rausing’s good looks and beautiful clothes — along with her husband and his friendly, bear-like countenance — had made the Rausings welcome participants on the London philanthropic scene. She was on several charity boards, focusing on those that helped fight drug addiction, but also serving on Prince Charles’ Foundation for the Built Environment.

Charles, no stranger to second chances, stood behind her after the embassy scandal, backing a decision to keep her on board as a trustee.

But evidence suggests that Eva Rausing’s drug use only intensified in the years after the embassy arrest. Recent photographs showed she had become quite gaunt, and her once stocky husband also recently appeared thin and furtive. He bore only a slight resemblance to his former self, when he would attend galas looking like an elegant, bearded European swain from an earlier era.

Hans Kristian Rausing was arrested in connection with suspected drug crimes and police want to question him about the circumstances of his wife’s death. He is currently receiving medical treatment in a London hospital. Police have not indicated that Eva Rausing’s death was a result of foul play or that a crime was committed.

Liz Brewer, a friend of Eva Rausing, told Sky News that Rausing’s problem had been “pushed under the carpet” for too long.

“She was totally addicted, obviously, and was trying to get off it,” she said.