Almost 30 police officers may be involved in a bribery case tied to an illegally operated online gambling network, according to a team of lawyers representing deputy national police chief Surachate Hakparn.

The lawyers said the 30 officers were suspected of taking kickbacks from the BNK Master network. It is the same gambling network from which Pol Gen Surachate has been accused of taking bribes, they said.

Pol Gen Surachate's lawyer said the team had checked the available evidence and 34 bank accounts linked to the network but found no connection to Pol Gen Surachate, also known as "Big Joke".

The Criminal Court last Tuesday approved warrants for the arrest of three officers and a civilian over suspected money laundering in connection with BNK Master, which was busted last year.

Some reports said the court also issued a summons for a high-ranking officer, later named as Pol Gen Surachate, over the accusations. However the lawyers denied this. Police had wanted the court to issue an arrest warrant for him but they had insufficient evidence, Surachate's lawyer said.

There were attempts to discredit Pol Gen Surachate because he was now the most senior candidate for the national police chief's job, he added.

The current chief is due to retire at the end of September.