"I did everything by the rules, but police commissioner General Kowit Wattana then changed the committee members to include city police officers," Seripisut said.

"He had no authority [to do this] because the law says a plaintiff must submit an objection letter to [my] supervisor, in this case, the prime minister or PM's representative."

After the raid on the "Por Pratunam" den, allegedly owned by businessman Paijit Thammaroj-pinij, by a special police taskforce in February, carried out without local police knowledge, a committee was set up to look into claims city police interfered in the case and told Paijit to sue the taskforce.

Kowit declined to comment on Seripisut's threat. Seripisut spoke at a press conference yesterday in which he announced progress on the  raid. He said 56 of 64 cars seized in the raid might be returned to their gambling owners later.