CHENGDU, China - China put an ex-police chief who triggered the Communist party's biggest scandal in years on "public" trial Tuesday, with the court saying he did not contest the key charges against him.

But foreign media were barred from the hearing, one day after a closed-door session, highlighting official sensitivity around the case of Wang Lijun -- who the court had said exposed "major violations of the law" by others.

Wang fled to the US consulate in Chengdu in February, setting off a crisis that saw the fall of his patron Bo Xilai and revealed deep divisions in the upper echelons of Chinese politics ahead of a generational transfer of power.

Footage on state broadcaster CCTV showed Wang sitting in a wooden chair in court Tuesday, looking relaxed and apparently speaking into a microphone.

Police cordoned off the area in front of the courthouse, with dozens of officers visible around the perimeter.

Wang "did not raise an objection" to the facts and charges of defection, abuse of power, bribe-taking or bending the law for selfish ends, said a statement from the court in the southwestern city of Chengdu.

The scandal led to the sacking of Bo, one of China's most high-profile political figures, and the conviction of his wife Gu Kailai for the murder of a British businessman. After Tuesday's trial was completed the court said it would announce its decision at a later date, and while a guilty verdict is considered almost certain, the sentence remains open to question.

The charges against Wang could carry the death penalty, but prosecutors said he was eligible to be shown leniency because he "made a significant contribution to the resolution of the Gu Kailai murder case", the court statement said.

Defence lawyer Wang Yuncai also argued for a reduced sentence, saying that her client "had a reason to choose to defect and he stopped committing the crime part way through", according to the statement.

It added that because the charges of defection and abuse of power related to state secrets, the court dealt with them in a separate closed hearing.

The document made no explicit mention of Bo, who has not been seen in public for months and is believed to be under house arrest, facing investigation by the Communist party for "serious" discipline violations.

Wang, 52, was drafted in by Bo, then the top Communist party official in the sprawling metropolis of Chongqing, to mastermind a crackdown on the local mafia, which Bo hoped would propel him into the top ranks of Chinese politics.

But relations between Bo and Wang turned sour early this year, months after British businessman Neil Heywood, a close associate of Bo's family, was found dead in a Chongqing hotel room.

Wang fled to the US consulate after an apparent dispute with the politician, reportedly telling officials that Bo's wife had murdered Heywood.

Gu was convicted of Heywood's murder by a Chinese court last month and given a suspended death sentence -- normally commuted to life imprisonment -- after a short trial that was thought to be subject to heavy political interference.

Analysts said before the trial that because of the Wang case's political sensitivity it would be carefully stage-managed by party officials.

"All we will see is what the party would like us to see," Steve Tsang, professor of contemporary Chinese studies at Britain's University of Nottingham, said in emailed comments. Not mentioning Bo in the statement, he said, "would imply that the leadership still cannot agree on what to do with him".

City University of Hong Kong political analyst Joseph Cheng told AFP: "It's a political arrangement, rather than an independent judicial trial.

"The verdict will relate to a political agreement amongst top Chinese leaders to limit the fallout from the Bo Xilai case."

The court statement did not mention widely reported allegations that Wang carried out extensive phone tapping of senior officials who visited Chongqing, even recording a conversation involving President Hu Jintao.

It only cited prosecutors saying that Wang had "used technical surveillance methods against many people" and "seriously damaged" China's legal system.