The mysterious death of the British businessman Neil Heywood in a Chinese hotel room initially exposed a tawdry tale of greed, blackmail and cyanide poisoning that led to the downfall of the Politburo member Bo Xilai.
Espionage can now be added to the ready-for-screenplay intrigue, with The Wall Street Journal reporting Tuesday that the well-connected Mr. Heywood was an informant for MI6, the British Secret Intelligence Service.
The revelation casts the affair in a new light, raising questions about how much Chinese security services knew about Mr. Heywood's activities and what led to his demise.
Citing unnamed sources, the Journal said Mr. Heywood, who had cultivated close ties with the family of Mr. Bo, regularly fed details about the private affairs of the ambitious Communist leader to a person who acknowledged being an MI6 officer to the Briton.
The news comes as the Chinese Communist Party is readying for its 18th Congress, starting Thursday in Beijing, which is expected to usher in a new generation of top leaders.
Mr. Heywood, a long-time expat who drove around Beijing in a silver Jaguar with "007" in the license plate, had been seen by some acquaintances as a fantasist.
Still, there had been speculations that he did some intelligence work because he sometimes prepared reports on Chinese companies for Hakluyt & Company, a consultancy started by former MI6 officers.
"China regards the private lives of its leaders as state secrets, and information about them and their families is prized by foreign governments trying to understand the inner workings of an opaque political system," the Journal said in its report.
British Foreign Secretary William Hague had taken the unusual step last April of issuing a denial, saying that Mr. Heywood was "not an employee of the British government in any capacity"– which did not exclude him from being an unpaid informant.
The Journal said Mr. Heywood's MI6 contact described him to a former colleague as being "useful," explaining that "a little goes a long way."
Mr. Heywood's role as an MI6 source could explain why the British government reacted so cautiously to news of his death while the Chinese authorities swiftly cracked down against Mr. Bo and his wife with explosive criminal accusations.
Nevertheless, days before his death, Mr. Mr, Heywood had told a friend, Tom Reed, that he had been estranged from Mr. Bo's family since 2010, the New York Times reported last spring.
The crime-fighting mayor of the Yangtze River metropolis of Chongqing, Mr. Bo was a flamboyant political star with hopes for a seat in the country's highest political echelon, the nine-member Standing Committee of the Communist Party.
Prime Minister Stephen Harper and the Desmarais business family were among the foreign dignitaries who courted him and former prime minister Jean Chrétien once called Mr. Bo an "old friend."
Mr. Heywood, who had lived in China since the early 1990s, had an insider's edge, having befriended Mr. Bo during his previous posting as mayor of the northern city of Dalian.
The boarding school-educated Mr. Heywood is credited with helping Mr. Bo and his wife, high-profile wife, Gu Kailai get their son, Bo Guagua, admitted to his alma mater, Harrow School.
Portrayed as a Communist princeling, Bo Guagua has been described as a Ferrari-driving playboy who hung out with movie star Jackie Chan and eventually got admitted to Harvard University.
In November last year, Mr. Heywood's body was found in a Chongqing hotel, a death initially blamed on excessive drinking.
The Chongqing police chief, Wang Lijun, then fled to the American consulate in Chengdu, in a short-lived attempt at defection. He eventually left the consulate but not before revealing the Heywood murder and triggering the end of Mr. Bo's ambitions.
Since then, Gu Kailai was reported by Chinese media to have confessed to killing Mr. Heywood because he was blackmailing her family.
Her husband was stripped of his party membership and he was accused of taking bribes and having "maintained improper sexual relationships with a number of women."
In an expeditious one-day trial this summer, Ms. Gu was said by the Xinhua news agency to have told the court that Mr. Heywood had threatened to harm her son during a dispute over a $22-million payment the British entrepreneur argued was owed to him.
She testified that she enlisted the help of Mr. Wang and then invited Mr. Heywood to dinner. She said she plied him with whisky and, when he became ill and asked for water, poured potassium cyanide into his mouth.
Shortly after Mr. Heywood's death, friends had wondered if he had been an agent for Britain's secret intelligence service.
"That would have worked for him," one friend told the New York Times, "in a strange way, the idea that he lived a life of intrigue."