Bo Xilai used his final session in court yesterday to accuse his former top aide Wang Lijun of being romantically involved with his wife.
While Bo stopped short of accusing Wang, his former police chief, of having an affair with Gu Kailai , he said they shared "an extremely special relationship".
He said the two key prosecution witnesses were "as inseparable as paint and glue", a Chinese phrase suggesting a sexual relationship.
Bo said the relationship was the real reason why Wang sought refuge at the American consulate in Chengdu in February 2012, an incident that exposed Gu's murder of British businessman Neil Heywood and blew open China's biggest political scandal in decades.
"[Wang's] obsession with Gu Kailai and their entangled affairs had reached such a stage he could no longer control it," Bo told the court in Jinan . "He intruded into my family. He hurt my feelings to the core."
Wang was sentenced to 15 years in prison on charges including defection, while Gu is serving a suspended death sentence for Heywood's murder.
Video: Bo trial ends, China prosecutors demand heavy sentence
Former Chongqing party secretary Bo acknowledged making mistakes but continued to deny criminal misconduct.
The former Politburo member has been charged with taking bribes, embezzlement and abuse of power, the last charge stemming from his response to revelations of Gu's involvement in Heywood's murder.
"I know that I'm far from being perfect. I'm subjective and ill-tempered. I have serious faults, and made serious mistakes," Bo said in his closing statement yesterday.
"But I never sought to cover up the [Heywood] case."
The Jinan Intermediate People's Court said it would announce the verdict at a later date. A source with direct knowledge of the case said a decision was expected early next month.
The five-day trial was the most closely followed trial of a high-ranking party member in recent memory and lasted longer than any since the Gang of Four's 40-day trial in 1980.
Bo, now 64, was once regarded as a front runner to join the Politburo Standing Committee.
On the last day of courtroom drama, Bo - the "princeling" son of one the party's "eight immortals", Bo Yibo - defended his family name and regaled the court with personal stories.
He said he never cared for money. "The long johns that I'm wearing now were bought by my mother in the 1960s," Bo said, suggesting he did not approve of the lifestyle Gu had created for their son, Bo Guagua .
"I have been working like a machine. I really don't have time to care about air tickets, hotel expenses and travel expenses," Bo said. He added: "The country did not pick me because I am a good accountant."
The prosecution pressed for a severe punishment in its closing statement, citing Bo's lack of remorse. "The defendant's crimes are extremely serious," the prosecutors said.
"He pleaded not guilty to the charges, and there are no extenuating circumstances suggesting lighter punishment. It must be dealt with severely according to the law."
Legal experts are divided on the verdict he faces, but many think his defiance at court will work against a lenient sentence.
The CCTV prime time newscast reported on the trial for the first time yesterday and People's Daily ran a commentary saying the trial had demonstrated the "legal way and mentality to fight corruption".
Beijing-based lawyer Li Fangping expected that Bo would receive a tougher punishment than disgraced Beijing party chief Chen Xitong and former Shanghai Chen Liangyu, who received 16 and 18 years' imprisonment respectively.
"The amount of money involved in the corruption is an important factor for sentencing, but the attitude of the suspect is also very crucial," Li said.
Mao Lixin, another Beijing-based lawyer, said a lenient sentence was usually given to those who pleaded guilty or showed remorse. "But Bo has denied all charges and there is no ground for leniency," he said.
Professor Wu Mingan, of China University of Political Science and Law, said it was likely that Bo would receive a suspended death sentence because of his feisty defence.
Additional reporting by Teddy Ng