Jamshedpur, April 19: Former joint secretary of Hindustan Copper Limited?s (HCL) Rakha Mines Labour Union, Sukhsagar Singh, who was critically wounded in an assault on Saturday night, succumbed to his injuries at the Tata Main Hospital late last evening.

Singh was attacked over an old enmity with a former HCL employee Mithilesh Singh over an alleged theft at the Rakha Mines township.

The police have arrested Mithilesh, the prime accused in the case. Six others are absconding.

On Saturday evening, a group of people led by Mithilesh launched a murderous attack on the trade union leader and his relatives at his house in Jadugora.

The accused, all relatives of Mithilesh, had attacked them with iron rods and lethal weapons, injuring the trade unionist and three of his relatives.

Soon after the incident the locals had taken the injured to a Jadugora-based hospital, from where he was shifted to the Tata Main Hospital.

Sukhsagar?s relatives, who have been admitted to the TMH, are his elder brother Ram Sagar Singh and nephews Prabhat Kumar Singh and Buchu Singh