The trial of New York Times researcher Zhao Yan has ended in Beijing, with no word on when a verdict will be reached.
Zhao Yan has been held for nearly two years (image: New York Times)
Mr Zhao, who has been held by the Chinese authorities since September 2004, denied charges of fraud and leaking state secrets.
The trial took place behind closed doors because of its sensitive nature.
Mr Zhao, if convicted of "providing state secrets abroad", faces a minimum of 10 years in jail. Authorities have given no details of the alleged crime.
However Mr Zhao is thought to have been detained in connection with a New York Times report about plans by ex-President Jiang Zemin to retire from his top military post.
At the time, Mr Jiang's intention would have been a closely guarded secret, and any leak regarded as a serious offence.
Mr Zhao, 44, has spent nearly two years in detention, while the authorities decided whether to pursue the case against him.
The charges against him were dropped in March, weeks before President Hu Jintao visited the United States.
But Mr Zhao remained in detention, and the case was revived last month.
If convicted, journalist Ching Cheong faces the death penalty
Lawyers for Mr Zhao expressed little hope he would be cleared of the charges now the case has come to court.
"Because these kinds of cases are very special, the court seldom accepts the opinions of the defence," Guan Anping, one of his two lawyers, told Reuters news agency.
Before joining the New York Times Mr Zhao, a Chinese citizen, worked for the magazine China Reform, where he wrote reports criticising abuse of poor farmers by officials.
A number of other journalists have been arrested in China under its national secrecy law. Ching Cheong, a Hong Kong-based correspondent for Singapore's Straits Times, was accused in August of spying for China's rival, Taiwan. If convicted, he could face the death penalty.
Chinese reporter Shi Tao, who worked for the Contemporary Business News in Hunan province, was sentenced in April to 10 years in prison for sending foreign-based websites the text of an internal Communist Party memo.
He is believed to have been jailed as a result of information Western internet firm Yahoo supplied to the Chinese government.