A speeding black Ferrari hit a wall on Beijing's North Fourth Ring Road in the early hours of March 18, then rebounded and crushed a railing on the other side of the road.
A half-naked man in his 20s died immediately and two young women - one naked, one semi-naked - were seriously injured.
Photos of the wreckage circulated online and many internet users took it as another drink-driving accident involving the "second-generation rich".
People speculated that the young man, reportedly surnamed Jia, was the illegitimate son of Chinese People's Political Consultative Conference chairman Jia Qinglin, who ranks fourth in the Politburo Standing Committee.
Wild stories began to spread that the trio were playing sex games in the car when the accident took place. Different versions of who was driving and who was in the front and back seats became the subject of gossip in Beijing's corridors of power.
But the accident, which happened just three days after Bo Xilai was sacked as party chief of Chongqing, has taken on a deeper significance.
It could become a political powder keg in the run-up to this autumn's 18th party congress, set to produce a new generation of leaders for the next decade.
That's because the real father of the victim is not Jia - and the scandal poses a grave threat to another key player in the high-stakes power game.
A mainland official and several Beijing media sources have told the South China Morning Post that the young man was actually Ling Gu, the son of Ling Jihua, chief of the General Office of the Communist Party's Central Committee and President Hu Jintao's principal aide until last week.
Ling is considered an important member of Hu's camp and was being groomed to become one of the People's Republic's sixth generation of leaders in another 10 years.
In a strong sign that the crash scandal has hurt Ling's chances of securing a seat at least on the Politburo, a reshuffle on Saturday saw him take over as head of the United Front Work Department, a largely symbolic post.
What is at stake is not just Ling's personal career. If the scandal becomes public knowledge on the mainland it will deal a huge setback to Hu's camp amid frenzied jockeying for position ahead of the party congress.
One of the bright spots of Hu's reign as party chief and state president has been his relatively clean image. He has always wanted to be remembered as an honest, graft-fighting leader, intolerant of corruption.
The suspicious circumstances surrounding the death of his most trusted aide's young son threatens to tarnish that image.
People will ask how Ling Gu could have afforded a 5 million yuan (HK$6.1 million) luxury sports car in the first place.
And it will only confirm the public belief that the children of senior officials have rich and decadent lifestyles beyond the wildest dreams of the people.
Hu's credibility and prestige would suffer collateral damage.
Ling is also a key chess piece in Hu's succession planning as he prepares to step down as party chief, and was expected to hold strategic positions to ensure Hu's continued influence.
It is perhaps for these reasons that the mainland official said an elaborate scheme was painstakingly stitched together to hide the real identity of the tragic young man in the crash.
The name that eventually appeared on the death certificate of the driver was a fake.
It remains unclear if it was a coincidence that the surname used was "Jia" - pronounced the same as the Putonghua word for "fake". But the choice of the surname led to the online gossip that the man who died was Jia's illegitimate son, the official said.
Some have speculated that it was a deliberate choice to throw people off track. But sources said Jia was angry that his name was implicated in the scandal and ordered a secret investigation, which quickly established that the driver was Ling's son.
The investigation report was quietly forwarded to former party chief Jiang Zemin - Jia's political patron and key ally. Jiang, who is retired but still wields a great deal of influence at the highest level, is competing with Hu in deciding the final line-up of the next generation of leadership.
In a telling development, Jiang reportedly sat on the report for nearly three months before taking it to Hu at a meeting.
Beijing media sources said they had known for a long time that Ling Gu was killed in the accident, but blanket censorship was immediately imposed.
"It was a gag order at the highest level. I have never seen any car accident that deserves an order of this level," a senior Beijing state media source told the Post.
Curiously, the English-language edition of the Global Times - run by the party mouthpiece People's Daily - did carry a report about the accident on March 19.
It confirmed all the basic details of the accident but stopped short of naming the victim.
It reported there was a blanket gagging order on the media and even quoted a "local resident" as questioning why such great efforts were being made to suppress the information. It quoted the resident as saying it proved only that the victim "must have a special background".
The two women, one Uygur and one Tibetan, both attended Minzu University, for students from ethnic minorities. One was paralysed and the other was seriously injured.
The cover-up is reminiscent of the botched attempt to hide the murder of British businessman Neil Heywood in Chongqing in November.
It led to Bo Xilai's downfall after his top aide, Wang Lijun, attempted to seek asylum at the United States consulate in Chengdu , Sichuan province, in February.
Heywood's murder unleashed the biggest political firestorm on the mainland for decades, with Bo's wife, Gu Kailai, found guilty of the crime.
Bo, who had been regarded as a strong contender for promotion to the Politburo Standing Committee, saw his own political career cut short. Another scandal of that magnitude would throw the once-a-decade power transition into total chaos. The leadership appears to be ill-prepared to deal with another crisis.
Whether Hu was informed about the case before his meeting with Jiang is unclear, although one rumour claims Hu was in the dark until Jiang briefed him about Jia's report.
It may never be known how much truth there is in that gossip, but it was only in early June that overseas gossip portals began to identity the victim as Ling Gu.
Overseas rumour mills, which have increasingly become platforms for different party factions to throw mud at each other, took different stances.
The overseas Chinese portal Boxun released several articles in June saying the man who died in the crash was Ling Gu.
But several days later, Yazhou Zhoukan, a Hong Kong-based political magazine, published an article denying Boxun's reports.
It said Ling Gu, who allegedly used the pseudonym Wang Ziyun while studying, was still alive. Yazhou Zhoukan's article was deleted from its website not long after it was published.
Another version of the crash also emerged recently in the Hong Kong media, saying that Ling Gu was indeed killed.
But it went on to report that he was not the driver or the owner of the Ferrari and that no sexual escapades had been going on in the Ferrari before the crash.
Also in June, postings on political gossip websites and magazine articles began to appear alleging that Ling Jihua's wife, Gu Liping , used a charity to reap profits - contributing to a sudden storm of negative publicity surrounding Ling.
Despite the mudslinging, Hu appears to have made up his mind to back Ling.
On June 12, days after Ling Gu was identified by Boxun, Hong Kong's pro-Beijing Wen Wei Po newspaper reported that Ling Jihua had been elected a party congress representative after capturing all the votes in his constituency, made up of agencies and organisations directly under the central government.
Observers see the timing of the Wen Wei Po report as a sign that Hu is backing Ling to sail through the political storm. A day earlier, Xinhua published a speech by Ling after his election.
Sources said that after the accident, Ling reportedly argued that he spent all his time serving Hu and had no time to look after his son properly.
But the damage has already been done. Ling was once tipped as a "dark horse" for elevation to the Politburo Standing Committee at this autumn's party congress, which would have ensured Hu maintained his influence after his retirement.
But analysts said the best Ling could hope for now was to become one of the 24 full members of the Politburo. Saturday's reshuffle seemed to suggest even this has become difficult.
"This accident will have a relatively large impact on Ling Jihua because his portfolio is not strong enough to enter the Politburo Standing Committee anyway … it will be difficult, no matter how hard his mentor [Hu] tries," political analyst Chen Ziming said.
"Now, after this incident, there will be a negative impact to his image. The power struggles are so intense that any small issue will be amplified, not to mention such a serious incident."
As well as criticising Ling and his wife for the playboy image of their late son, political rivals also attacked them for putting on poker faces and going to work the day after he died.
Ling also accompanied Hu to South Korea, Cambodia and India less than two weeks after the accident.
But a businessman who has close ties with senior Beijing officials said Ling was depressed for a long time afterwards.
Johnny Lau Yiu-siu, a Hong Kong-based political analyst, said Hu would not have had enough influence to help Ling jump the queue and enter the Politburo Standing Committee even if the crash had not happened. But the crash would not give Ling's rivals the leverage to topple him completely, either.
"In the end, compromise will play a more important role in Chinese politics," Lau said.
Correction: The story identified the two women with Ling Jihua's son at the time of the accident as from "Minzhu University." The correct name of the university is "Minzu University".