A South Korean court has sentenced Samsung Electronics board chairman Lee Sang-hoon to 18 months in prison for sabotaging labour union activities.

Axar.az reports citing foreign media.

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

Prosecutors said Samsung executives had used several tactics to target union activities, including closing sub-contracted firms with active unions.

Samsung has not yet commented on the ruling.

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 on Tuesday focused largely on efforts by officials to undermine union activities at the customer service unit when Lee was serving as chief financial officer.

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, prosecutors said.