BEIJING — Now that the murder trial of Gu Kailai has ended, far more detailed accounts have emerged from inside the courtroom of the case that prosecutors built against Ms. Gu, the wife of one of China’s most ambitious leaders. The accounts show her plotting with allies, including the local police chief, to protect her son from what she saw as the blackmail demands of the British business associate she is believed to have killed.


Prosecutors presented evidence that the Briton, Neil Heywood, had demanded tens of millions of dollars from Ms. Gu’s son, locked him up in a residence in England and sent an e-mail threatening to “destroy” him. In response, Ms. Gu sought help from the local police chief, who refused to go along with her plan to get rid of Mr. Heywood and later secretly recorded her confession after she poisoned Mr. Heywood.


The tale gave a rare glimpse into the darkest corners of a Chinese ruling family. It told of a dramatic struggle between Ms. Gu, 53; her Oxford- and Harvard-educated son, Bo Guagua, 24; and Mr. Heywood, 41, a longtime friend and business associate whose body was found in November in a hotel in Chongqing, the fog-wreathed western metropolis governed for more than four years by Ms. Gu’s husband, Bo Xilai, a Politburo member.


Ms. Gu and a family aide, Zhang Xiaojun, stood trial on Thursday in Hefei, Anhui Province. No verdict was delivered, but a court official said the defendants did not object to the charges. The details of the court arguments that emerged Friday were not included in a terse statement issued the previous day by officials.


A detailed account of the trial was posted on Friday morning on renren.com, a social networking Web site, by Zhao Xiangcha, a university student in Anhui who said he had been inside the courtroom. He said he had written it from memory after the seven-hour trial had adjourned. Most of the account, which was deleted from his renren.com page around noon, was confirmed in telephone interviews with Li Xiaolin, a lawyer for Mr. Zhang, and another lawyer inside the courtroom. Late Friday, Xinhua, the state news agency, published an account with many of the same details.


Mr. Zhao wrote in his post that Ms. Gu, whose hands shook during the trial, confessed to murdering Mr. Heywood.


Many legal experts say the trial was political theater and little more than a forum to present an official narrative of the crime. The session raised as many questions as it answered. For starters, it failed to address the towering issue of what Bo Xilai knew of the crime and whether he had a role in its execution or cover-up.


Bo Guagua declined to comment for this article. Mr. Heywood’s mother said before the trial that the case was rooted in palace intrigue. Mr. Heywood’s wife, who is Chinese, could not be reached for comment. People at the trial said the defense lawyers argued that the poison might not have been enough to kill Mr. Heywood, and that he probably died instead from drinking too much alcohol that night. The lawyers also said that Ms. Gu suffered from manic depression and mild schizophrenia and was not in full control of her actions.


According to the courtroom accounts, Mr. Heywood, a longtime resident of China, met Bo Guagua in England around 2003. The two became close. Mr. Heywood hoped his relationship with the Bo family would help further his business ambitions in China.


Mr. Heywood was introduced to Xu Ming, a young billionaire and friend of the Bo family in the northeast city of Dalian, where Bo Xilai had been mayor, and to a “princeling” executive at a state-owned enterprise surnamed Zhang. The businessmen later entered into real estate ventures that included a property deal in France and projects in Chongqing, where Mr. Bo became party chief in late 2007.


Prosecutors said that when the Chinese ventures failed because of political interference, Mr. Heywood last year demanded from Bo Guagua 14 million pounds, about $22 million, which was 10 percent of the money Mr. Heywood had expected to earn if the ventures had succeeded, according to Mr. Li. He added that the prosecutors said Mr. Heywood sent threatening e-mails to the younger Mr. Bo — in one, Mr. Heywood wrote in English that he would “destroy” Mr. Bo. The e-mails were projected on a screen during the trial.


Mr. Heywood then locked Mr. Bo up in a residence in England, according to Mr. Zhao’s account of the prosecutors’ case. Mr. Bo called his mother and told her about the abduction.


Back in Chongqing, Ms. Gu asked Wang Lijun, the police chief, for help, but Mr. Wang said he could do nothing. It then occurred to Ms. Gu that she needed to get rid of Mr. Heywood to protect her son, whom she called “little rabbit” in e-mails, prosecutors said.