A South Korean court on Tuesday sentenced the Board Chairman of Samsung Electronics,  Lee Sang-hoon to 18 months in prison for sabotaging labour union activities.

Lee and about 25 other defendants were convicted of violating labour union-related laws.

The verdict followed a ruling last week which saw Samsung Electronics Vice-President, Kang Kyung-hoon sentenced to 16 months in prison on charges of union-busting.

Although Samsung is yet to comment on the ruling, prosecutors said executives of the electronics company had used several tactics to target union activities, including closing sub-contracted firms with active unions.

The Seoul Central District Court said plans to stop union activities had been masterminded by executives in the firm’s now-defunct elite strategy group.

The case focused largely on efforts by officials of the company to undermine union activities at the customer service unit when Lee was serving as its Chief Financial Officer.

The prosecutors said other tactics used by the defendants to target unions included finding out sensitive information about union members to convince them to leave and delaying negotiations between labour unions and management.

The jury held that there were countless documents which detailed the tactics used by the officials to undermine union activities which were distributed to affiliates by the elite unit.

“While Lee claims there were many areas he did not know much about, we cannot give him immunity only due to the fact that he was not aware of the peripheral areas,” the judge was quoted as saying.

The extent and details of the charges against the defendants found guilty were however varied.