DETROIT – A former General Motors Co engineer and her husband, charged with conspiring to steal the automaker’s trade secrets, were seen throwing out bags of shredded documents in a shopping plaza in 2006, FBI agents said on Tuesday.

Shanshan Du, 53, the former GM employee, and her husband, Yu Qin, 51, were charged in 2010 in a seven-count indictment with trying to steal GM trade secrets related to hybrid vehicles to pass on to China’s Chery Automobile Co. The trial in U.S. District Court in Detroit began on Monday.

Several FBI agents described in court on Tuesday how they watched the defendants in May 2006 driving to a shopping plaza in Troy, Michigan, to throw away the bags of shredded documents. The agents also described seizing several computers, files and detachable hard drives from the couple’s Troy home office.

Frank Eaman, Qin’s lawyer, said the documents in question were not trade secrets.

Qin and Du, who worked as a GM engineer, are accused of taking confidential GM information on hybrid technology and trying to pass it to Chinese automakers through a small firm they owned called Millennium Technology International, according to court documents.

Du is accused of copying thousands of GM documents to an external hard drive five days after the automaker offered her a severance agreement in January 2005.

She left GM’s advanced technology group in March 2005. In August, Qin and Du proposed a joint venture on hybrids to China’s Chery in a series of emails, according to court documents.

Then in November 2005, Qin, who had been working as an electrical engineer in Troy, applied for jobs as a hybrid engineer, claiming on his resume that he had invented some of the stolen GM technology, according to court documents.

The couple were required to surrender their U.S. passports and cannot leave the Detroit area without court permission.

Each defendant faces a count of conspiracy to possess trade secrets without authorization and two counts of unauthorized possession of trade secrets, as well as three counts of wire fraud. In addition, Qin faces a charge of obstruction of justice.

The trade secret counts carry a penalty of up to 10 years imprisonment and a $250,000 fine. The wire fraud counts and an obstruction charge each carry a penalty of up to 20 years in prison and a $250,000 fine.

GM declined to comment on the ongoing case.

The case is In re: U.S. v. Qin, U.S. District Court, Eastern District of Michigan, No. 10-cr-20454.

(Reporting by Eddie Allen in Detroit; editing by Prudence Crowther)