The warrant was issued for Yutthana Kularpmoung on charges of conspiring with another person to murder, conspiring to have a gun and ammunition in his possession without permission, conspiring to carry the weapon into a public place, and conspiring to assault another person.

Yutthana remains at large.

Yutthana and Jirapan Koysap, 35 – who is in custody after being arrested on Tuesday in the border area of Surin province – went to the stadium to attack Udom last Friday afternoon. When security guard Anucha Pathumma, 24, tried to intervene, Yutthana shot him dead.

Udom, 59, suffered head injuries.

Contrary to previous police suspicions that the duo was hired by a boxing gym owner who may have been angry over the result of a contest on Tuesday, Jirapan told police he attacked Udom for his own reasons.

Jirapan said he lost Bt20,000 in a boxing bet and held Udom accountable. He said he asked Yutthana to help him attack the referee on a motorbike, but he did not know that Yutthana was carrying a loaded gun.