Wang Lijun is charged with defection, abuse of power and bribe-taking.
The trial was due to begin Tuesday but began earlier, unannounced, at a court in the southern city of Chengdu.
Wang Lijun’s flight to the US consulate in the city in February triggered events leading to the downfall of powerful politician Bo Xilai.
On the second day of the hearing, foreign journalists will not be given access to the public part of the trial.
The trial had been expected to start on Tuesday, but Wang Lijun’s lawyer Wang Yuncai, who is not related to her client, said the hearing had started at 08:30 local time on Monday.
A brief report in state media said Wang Lijun is standing trial for ”bribe-taking and bending the law for selfish ends” on Tuesday.
”The Chengdu City Intermediate People’s Court held a closed-door trial Monday on Wang’s two other charges of defection and abuse of power,” the Xinhua news agency report said.
On Tuesday, security officials stood guard outside the court.
It is not clear how long Wang Lijun’s trial will last but that of Bo Xilai’s wife, Gu Kailai, lasted a day.
According to the UK Foreign Office, Wang Lijun made allegations about Neil Heywood’s death while at the US consulate.
Shortly afterwards, Bo Xilai was sacked and Gu Kailai was accused and convicted of the murder of Neil Heywood and given a suspended death sentence.
Chinese media has been quiet on the trial and searches for Wang Lijun’s name and related terms have mostly been blocked on China’s Twitter-like weibo microblogs.
However, netizens have been using pseudonyms such as “head nurse” – a term that puns on ”deputy mayor” in Chinese – to make comments. Wang Lijun was the deputy mayor of Chongqing.
A microblog user in Guangzhou said: “Good luck, head nurse.”
“There should be a public holiday today, and the head nurse’s trial should be broadcast live on TV so people can have a chance to learn what is the rule of law,” said a microblog user in southern Zhuhai city.
The trial is taking place ahead of a key party leadership congress in China, expected in the coming weeks.
Earlier Chinese state media reports said the evidence against Wang Lijun was “concrete and abundant”.
The indictment against him said he knew that Gu Kailai was a murder suspect, but “consciously neglected his duty and bent the law for personal gain”, Xinhua news agency reported.
Wangn Lijun’s flight to the US consulate had proved an embarrassment for China and threw up issues involving diplomacy and state secrets, analysts say.
But most analysts expect him to be given a suspended death sentence, similar to the one meted out to Gu Kailai, reports say.
At a separate trial on 10 August, four senior police officers from Chongqing admitted to charges of covering up evidence linking Gu to the murder. A court official said they had been given terms of between five and 11 years in prison, AFP reported.
Bo Xilai, Wang Lijun’s former boss in Chongqing, had been tipped for promotion to the top leadership ranks at the party congress before his downfall.
He has not been seen in public since the scandal erupted. He is said to be under investigation by the party’s disciplinary officials.
Wang Lijun, 52, began his career in law enforcement in the Inner Mongolia Region in 1984 and moved to the southwestern city of Chongqing in 2008.
He had a reputation for being tough on organized crime and was once the subject of a TV drama called Iron-Blooded Police Spirits.
NUySOPQb3bg B_PD_HOGpnEThe US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…