BEIJING -- More than a decade ago, a mysterious foreign buyer looking for property in France settled on a villa along the sun-bleached Riviera. The house later became tied to a British businessman, Neil Heywood, whose death in 2011 in China set in motion a political crisis within the upper ranks of the Communist Party.
That villa in Cannes has emerged as a major aspect in a criminal case against Bo Xilai, a fallen Communist Party aristocrat, which has presented the party with one of its biggest challenges since the Tiananmen Square protests of 1989.
Officials intend to present the villa as evidence of significant bribetaking in a coming criminal trial that is expected to signify the end of Mr. Bo's political career, according to three people with ties to the Bo family. Mr. Bo's downfall began when accusations emerged that his wife had murdered Mr. Heywood in 2011. The trial of Mr. Bo, who is facing three criminal charges, is expected to begin within weeks or days.
Political analysts say the trial's probable outcome, a lengthy prison sentence for Mr. Bo, has no doubt already been determined by party leaders.
The most serious charge against Mr. Bo, 64, is that of taking bribes worth more than $3.5 million, mainly from a young billionaire, Xu Ming, who was listed by Forbes in 2005 as China's eighth-richest person. The charge rests largely on the villa, which the Chinese authorities allege was bought by Mr. Xu and given to the Bo family, according to the three people with knowledge of the case, who spoke on the condition of anonymity because of the delicate politics of the trial.
French documents show that people close to the Bo family have been involved with the villa since 2001. Patrick Henri Devillers, a Frenchman who knew the family when Mr. Bo was the mayor of Dalian in the 1990s, is listed in a property assessment document as a current owner of the home, and he was appointed head of a company apparently created to buy the property in 2001, according to an earlier document. That management company, Résidences Fontaine St. Georges, is registered at the villa's address, 7 Boulevard des Pins, and Mr. Heywood, the Briton and Bo family friend, was listed in court documents as the manager of the company from 2007 to June 2011, five months before he died in China.
The villa, surrounded by white concrete walls, is in a leafy neighborhood whose yards have palm trees and swimming pools. An audit of the property presented to a French commercial court put the villa's base value in December 2010 around $3.5 million.
Until midsummer, a court-appointed lawyer had been indicating to the Bo family that Mr. Bo would face two charges: bribetaking involving about $1.1 million in payments from Mr. Xu to the Bo family, and abuse of power for Mr. Bo's dismissal of Wang Lijun as police chief of Chongqing, in what officials called an attempt to impede an investigation into Mr. Heywood's death. As Chongqing's party chief, Mr. Bo ran the municipality for four years until his dismissal in March 2012, when the murder scandal unfolded.
Right before the charges were announced in late July, an internal document circulating among officials indicated that the bribetaking amount was more than $3.5 million -- three times what the Bo family had been told.
The additional amount included the value the authorities attached to the villa. Other amounts cited as bribes in the indictment included around $850,000 in travel and other expenses said to have been paid by Mr. Xu in the name of Mr. Bo's wife and younger son. An embezzlement charge was also included; people briefed by lawyers said the amount was five million renminbi, or $800,000, which was missing from a Dalian government construction agency.
"These sums should not be considered a real and true accounting of the money, but rather the most appropriate amount as calculated from a political perspective," one family associate said. "Originally we'd been hearing it was six million-plus renminbi, but a lot of people felt that amount was too small."
In recent bribetaking cases involving senior officials, amounts have been much larger. Last month the former railway minister pleaded guilty to taking 64 million renminbi, or more than $10 million, in bribes. He was given a suspended death sentence, equal to life imprisonment.
One close family associate denied that the Bo family had ever owned the villa or benefited from it. The person said Mr. Xu had bought a villa in Cannes with the help of Mr. Devillers, whom Mr. Xu had met in Dalian through the Bo family. When Mr. Devillers moved to Cambodia from China, he handed management of the property to Mr. Heywood, the associate said.
French documents show that Mr. Devillers was indeed appointed manager of the company at its founding in 2001, six years before Mr. Heywood was named manager. The managers of a Canadian company said it had founded the Résidences Fontaine St. Georges company for the purpose of buying the villa.
Joanne Bergman, director of the Canadian company, Investissements Custodian Inc., an investment holdings company incorporated in Montreal, said in a telephone interview that her role in the purchase of the property had been as a trustee; her company held shares in Résidences Fontaine St. Georges on behalf of a trust whose identity she never knew, she said.
Ms. Bergman's husband, Jean-Marie, said the couple had been paid a "small fee" for holding the shares, which they ceded several years ago.
An intermediary whose identity Mr. Bergman declined to reveal had contacted them to ask that they assist in buying the villa, he said. It was at the behest of that intermediary that they appointed Mr. Devillers to become the first manager of Résidences Fontaine St. Georges, the Bergmans said.
French court documents show that in June 2011, Mr. Heywood was removed as the manager of Résidences Fontaine St. Georges at the Cannes address. That title was given to Feng Jiang Dolby, a former variety show host, writer and state television journalist. . Ms. Dolby, who married a Briton and is a British citizen, has a residence listed in Surrey, England, and is well known to fans by her Chinese name, Jiang Feng.
Chinese job Web sites list an educational consulting company that Ms. Dolby founded as being directly tied to Dalian Shide, Mr. Xu's conglomerate.
There was no number listed at the Surrey address for Ms. Dolby, 43. Mr. Xu has been detained since Mr. Bo was stripped of his post in March 2012.
Edward Wong and Jonathan Ansfield reported from Beijing, and Scott Sayare from Paris. Bernadette Murphy contributed reporting from Paris.
This article originally appeared in The New York Times.