Police believe a family inheritance dispute could be behind the murder of a rubber plantation owner at dawn in Thung Song province on Tuesday.
Montri Pengsakul had a violent argument with one of his cousin three months ago, police said.
They suspects that the same cousin hired the person who shot dead Montri.
Witnesses said Montri rode out alone to work on his large plantation. Two pick-up trucks suddenly closed in on him and several shots were fired.
Police said it is also possible the killers were sent by one of Montri’s business rivals.
Police are bringing in Montri’s cousin in for questioning.