Ousted Chinese political star Bo Xilai denied the first of the allegations against him Thursday as he went on trial for bribery, embezzlement and abuse of power in the country's highest-profile prosecution for decades.

Bo was charged with abusing his political powers to cover up his wife's murder of a British businessman in 2011, according to the Twitter-like weibo account of the Intermediate People's Court in Jinan, in eastern China.

A picture of the once powerful-politician posted online by the court showed him standing in the dock wearing an open-necked white shirt and looking pensive, his hands crossed in front of him.

Prosecutors said he "received 21.8 million yuan" ($3.6 million) in bribes while mayor of the northeastern port city of Dalian, governor of Liaoning province and national minister of commerce, and that he also embezzled another 5.0 million yuan of public funds.

Bribes were received through Bo's wife Gu Kailai and their son Bo Guagua, they said.

In a statement the court said that Gu -- who was handed a suspended death sentence for murder last year -- provided evidence relating to the bribery charges.

But Bo denied one of the elements, that he had accepted more than 1.0 million yuan in bribes from Dalian-based businessman Tang Xiaolin, saying he had "confessed against his will" while under interrogation by the ruling Communist party's internal disciplinary body.

"I was willing to accept my legal responsibilities," he said. "But I was not at all aware about the details of the matter. My mind was blank at the time."

His refusal to admit the charge contrasted with previous political cases in China including those of both Gu and Bo's former police chief Wang Lijun, who confessed at their trials last year.

Bo's own long-awaited trial had been expected to proceed swiftly, with a guilty verdict all but certain and the sentence believed to have been decided beforehand, but Thursday's development raised the prospect that he may not accept his fate quietly.

The prosecution called for Bo to be punished according to a law that prescribes a minimum of 10 years in jail for taking bribes of more than 100,000 yuan.

"I hope the judge can deal with the case reasonably and fairly," the court quoted Bo as saying.

Bo was once the top Communist official in the southwestern megacity of Chongqing and one of 25 members of the ruling party's Politburo.

Authorities are touting the trial as proof of its intent to crack down on corruption.

But details about the scandal, which erupted in the build-up to a once-in-a-decade leadership handover that saw Xi Jinping elevated as party chief, have also exposed the high-flying lifestyles and murky dealings of China's political elite.

It also revealed factional divisions within the party, and the court proceedings remain tightly controlled.

Analysts say Bo's revival of the trappings of China under Mao Zedong -- including mass concerts singing "red" songs -- in Chongqing alarmed sections of the top leadership, who saw the campaigns as a brash return to a bygone era of strongman rule.

"(Bo) was an outlier - who was obviously out for himself and sought publicity like a western politician and frankly wasn't well liked," said James McGregor, chief of greater China operations for consultancy APCO.

"Getting him out of the way was probably very important for the leadership," he told AFP.

But Bo's populist politics still draw supporters -- one man held up a portrait of Mao outside the court and another onlooker surnamed He, who works part of the year in Chongqing, openly praised the fallen leader in front of a row of police.

"If this were a matter of justice, would they be so nervous?" he said, referring to the scores of blue-uniformed police who blocked roads around the entrances of the court in Shandong province, far from Bo's power bases, early Thursday.

"It doesn't matter how he is sentenced, it matters how history is written," He added.

Hundreds of passersby stopped to watch outside the court, some capturing the scene on their smartphones, as cars, buses and ambulances occasionally drove in.

The galleries were packed, the court said, with five relatives of the accused present, two assistants, 19 journalists and 84 members of the public. But no foreign media organisations were granted entry.

The politician's dramatic downfall began in November 2011 when British businessman Neil Heywood was found dead in a hilltop hotel room.

Gu was last year given a suspended death sentence -- normally commuted to life imprisonment -- for Heywood's murder. Bo's police chief Wang Lijun, whose flight to a US consulate blew the scandal open, got 15 years in jail for his role in covering up the killing, defection and other crimes.