Police arrested 311 people last year for selling trade secrets, with most information going abroad ending up in China, said police officials Monday.

According to the National Police Agency, the numbers are up from 154 people in 40 cases in 2010.

Police report that secrets going abroad increased by 167 percent during the same period.

Of the total cases 29 percent involved secrets being sold abroad, with 58.3 percent of those going to China, followed by the U.S., Germany, Spain and England.

Medium and small-size businesses were the biggest victims making up 89.3 percent.

Police report that the most common methods of selling trade secrets involved storage devices including USB thumbdrives, hard disks and smartphones, followed by emails.

Some 59 percent of the cases involved employees taking company secrets with them after resignation.

“We will stop companies from unfairly receiving profits by strengthening investigative efforts against such companies and develop a confiscation policy before indictment,” said one police official who declined to be named.

By Robert Lee (robert@heraldcorp.com)