Andrew Kissel's brother died in the infamous “Milkshake Murder”, when his wife served him a strawberry drink laced with sedatives before bludgeoning him with a statuette in their flat in Hong Kong.

A year later Andrew Kissel himself was found, bound to a chair and gagged, in a pool of blood in his Connecticut mansion.

Now police have arrested his chauffeur and the chauffeur's cousin for a killing that could prove even more bizarre than the Milkshake Murder: detectives are considering the possibility that this was a case of “suicide-for-hire”, in which Mr Kissel, 46, arranged his own death so that relatives could benefit from an insurance payout.

Mr Kissel, whose body was found in April 2006, was once a property tycoon who owned a $3 million (£1.5 million) yacht, a jet, a ski chalet in Vermont and a fleet of classic sports cars. But his life had been ruined by charges that he embezzled $3.9 million from the Park Avenue building where he lived and served as treasurer.

His wife, Hayley, a stock analyst and former mogul skiing world champion, had left him and he was about to plead guilty to multimillion-dollar fraud charges that could have sent him to jail for a decade. With creditors circling, his main asset was a $15 million life insurance policy benefiting his children, Ruth, then 8, and Dara, 6.

In making the arrests, police offered no motive for Mr Kissel's murder. But investigators refused to rule out an extraordinary “suicide-for-hire”.

“If it ends up being the case, that's fine,” David Ridberg, the Greenwich police chief, told a press conference. “If it doesn't end up being the case, that's fine, too.” He said that the suspects would face murder charges and could not use “suicide-for-hire” as a defence.

Carlos Trujillo, 47, who served as Mr Kissel's personal assistant and chauffeur for six years until the day of his death, was arrested on charges of conspiracy to commit murder in nearby Stratford, Connecticut. His cousin, Leonard Trujillo, 21, was arrested at his home in Massachusetts.

Police said that Carlos Trujillo, a Colombian immigrant, had been top of their list of suspects from the start.

“The information we had in the beginning was that he was the last one to see him alive so that seemed a natural place to start,” Mr Ridberg said.

The Hartford Courant reported that Mr Kissel had used the Trujillo family in financial transactions to hide his dwindling assets from creditors and his estranged wife.

As he was led out of police headquarters in handcuffs, Carlos Trujillo was asked if he had killed his former boss. “No, I didn't,” he replied.

“I think Carlos is here because he is the easiest suspect,” Lindy Urso, his lawyer, told reporters.

The 2003 killing of Mr Kissel's younger brother, Robert, a Hong Kong-based investment banker, mesmerised the former British colony with revelations of his cocaine use and online searches for gay sex and bondage. His wife, Nancy, was jailed for life.

Andrew Kissel and his wife took in the couple's three children until their marriage also collapsed.

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