More than 100 illegal Myanmar migrants were arrested when officials raided rented houses in Hat Yai district on Thursday night following the murder of a local man.
Officials said 109 illegal Myanmar nationals were arrested from 12 rooms at two rented houses.
Police had earlier arrested about 60 illegal migrants following the discovery of the gagged and bound body of Maddol Binsan, 40, on Wednesday morning.
Police believe he was murdered and buried in forest near a golf course after he came across a camp of illegal Myanmar job seekers waiting to be smuggled to Malaysia.
He was last seen in surveillance camera footage leaving his house to go fishing on Tuesday afternoon.
The head of tambon Banphru said smugglers and illegal migrants were the prime suspects.
Maddol had not had any conflict with any local people.
The murder had scared local people, because most of them worked as rubber tappers, and rose early to go into the forest and work at rubber plantations, the head said.
