A Chinese scholar who the US helped free from a Chinese prison has pleaded guilty in an American court to sending prohibited hi-tech equipment to China.
Gao Zhan has been helping the US Government
Rights activist Gao Zhan admitted unlawfully exporting 80 microprocessors which could be used in weapons systems.
Gao, a US resident alien who is due to be sentenced in March, was convicted by China in 2001 of spying for Taiwan.
She had spent more than five months in jail in China before being released under intense pressure from Washington.
At the US district court in Virginia, Gao also pleaded guilty to tax evasion. Her husband Xue Donghua admitted the same charge.
Federal prosecutors said Gao had been selling items to China that were on a list requiring permission from the US government to be exported.
She is said to have received $1.5m over four years for selling the microprocessors and other items to China.
A Justice Department official said she did not report the majority of the money she made on her income tax returns.
Gao faces a maximum of 37 months in prison, with her husband facing up to a year in prison, and a fine of up to $100,000.
However, prosecutors say they will ask for a reduced sentence because she has been helping the US identify those in the Chinese Government who are seeking to import controlled goods.
Gao Zhan, a Chinese sociologist based in the US, was one of a number of scholars found guilty by China of spying for Taiwan.
She was sentenced to 10 years but was freed just over five months later on medical grounds.
Her release, in July 2001, came days before a visit to China by the US Secretary of State Colin Powell.
The US had put intense pressure on China over the case, expressing its dismay at the verdict and lack of transparency in the process.
It came at a time of high Chinese-US tensions, and her release was seen as an olive branch to Mr Powell before his arrival in Beijing.