"Wang Lijun is fine, physically and mentally," she added.
The trial comes seven months after Mr Wang made a sensational dash for Chengdu's United States consulate, triggering one of China's most serious political scandals in decades and a diplomatic crisis spanning three continents.
Mr Wang, 52, was once the right hand man and confident of Chongqing's powerful party chief Bo Xilai, whose wife, Gu Kailai, was given a suspended death sentence in August for the murder of British businessman Neil Heywood.
But in February Mr Wang fled Chongqing and sought refuge in Chengdu's US consulate, where he is said to have revealed that Ms Gu had poisoned Mr Heywood. After over 30 hours inside, Mr Wang was forced to surrender to Chinese authorities but he had already set in motion a political scandal that continues to rock Beijing in the lead up to this year's crucial once-in-a-decade leadership transition.
On August 9, Ms Gu was tried for poisoning Mr Heywood, blaming her actions on a "mental breakdown" she had suffered after becoming addicted to "hypnotic drugs".
Ms Gu reportedly confessed to plotting Mr Heywood's murder after he threatened to "destroy" her son during a financial row, a claim disputed by friends of the British businessman. She did not contest claims she had lured Mr Heywood to a hotel room in Chongqing before poisoning him with cyanide.
During Ms Gu's trial details also emerged of Mr Wang's alleged involvement in an elaborate cover-up attempt. At one point Ms Gu's defense claimed Mr Wang and Ms Gu had conspired to have Mr Heywood shot and framed as a drug trafficker, according to one lawyer who was present at that trial.
So far Mr Bo has only been accused of violating "party discipline".
Before Mr Wang's trial began state media announced he had been charged with "defection, abuse of power, violating the law for personal favor and accepting bribes." As the flamboyant former police chief and vice-mayor of Chongqing stood in the dock inside the courthouse, dozens of plain-clothes police and security officials equipped with radios and video cameras patrolled the streets outside.
One official from the Public Security Bureau demanded that the Daily Telegraph stop photographing the courthouse claiming it needed permission to do so.
Si Beibei, a government propaganda official, denied the trial had already started and said proceedings would only start at 8am on Tuesday.
She said the heavy security presence outside the courthouse was a "security rehearsal".
In the lead-up to Mr Wang's day in court China's state-run media praised authorities for allowing an "open" trial.
But Ms Si confirmed Tuesday's trial would effectively be closed to the foreign media.
"It is a public trial but not open to the media," she said outside the courthouse which was cordoned off and surrounded by security forces and plainclothes security agents.
Ms Si said a press conference would be held "probably late afternoon [on Tuesday], after the trial is finished." "You will get news at the meeting and may [be] allowed to raise questions." "Someone who makes crimes should get this treatment," she said.