WASHINGTON, July 29 -- A federal judge has dismissed charges against a Chinese woman who was accused of helping to steal high-tech corn seeds from U.S. companies.

Stephanie Rose, a Judge of the U.S. District Court for the Southern District of Iowa on Tuesday dropped Mo Yun from the trade-secrets case based on the request of the federal prosecutors.

Prosecutors said they withdraw charges against Mo because the Judge Rose has ruled the instant electronic-messages, the major evidence against Mo couldn't be used during her trial.

Rose said the time of the messages found in Mo's elder brother Mo Hailong's computer were from 2007 to 2008, too old to be used at trial and they were incomplete after being cut and pasted into a word file which couldn't be proven to be true.

The court ordered the government to return Mo's passport and immediately stop all court-directed electronic monitoring. Mo's attorneys Terry Bird and Gary Lincenberg said as the mother of two small children in Beijing, Mo plans to leave the United States this week.

Mo, wife of Shao Genhuo, chairman of Beijing-based Da Bei Nong Science and Technology Group was arrested last summer. Her brother Mo Hailong was arrested in December 2013.

The trade-secrets case include Mo, her brother Mo Hailong and five other Chinese. They were accused of stealing patented corn seeds from U.S. seed companies including Pioneer and Monsanto and ship those seeds to China to benefit Chinese seed companies from 2007 to 2013.