Si Sa Ket chairman Thanet Kruerat claimed Wednesday that four of his players were involved in match-fixing.
The Football Association of Thailand (FAT) and Royal Thai Police announced on Tuesday that 12 people are under investigation for match-fixing.
Among them are five Thai League 1 players -- four from Navy and one from Nakhon Ratchasima, a referee, a linesman and Si Sa Ket director Therdsak Boonchu.
The 12 are accused of "receiving money or benefits in order to throw a game" or influencing others to throw a game or manipulate the score.
They were arrested and released on bail.
Thanet told a press conference that he and the club had nothing to do with the illegal practice and dismissed reports that Therdsak was his close aide.
He said he knew Therdsak, a Si Sa Ket native, only because someone asked him to find a job at the club for him.
Thanet claimed that four Si Sa Ket players -- three defenders and a goalkeeper -- were involved in match-fixing last season.
"I can't believe that they were involved in match-fixing," said Thanet.
Three of the players are out of contract while the other is still with the Koupreys, he said.
Thanet admitted that the club's reputation was tarnished by the scandal. "We now have to be careful in recruiting players and officials," he said.
Si Sa Ket were relegated from the top flight to T2 at the end of last season which concluded last weekend.
Meanwhile, former Thailand striker Piyapong Pue-on said match-rigging is a "cancer of football".
The match-fixing investigation could hurt Thai football as fans would become fed up and sponsors would be scared away, he said.
This happened in neighbouring countries such as Indonesia, Malaysia and Singapore, said Piyapong, who played for Malaysia's Pahang among other clubs.
AFC praises FAT
Shaikh Salman bin Ebrahim Al Khalifa, the Asian Football Confederation (AFC) president, has congratulated the FAT on its tough stance against match-manipulation in the country.
Hours after Shaikh Salman launched the AFC's latest weapon in the battle against match-fixing -- the AFC Integrity App developed with Sportradar -- he commended the FAT on its "determination to target and punish any element that attempts to tarnish the image of our game".
The FAT, in conjunction with the Royal Thai Police, has promised tough action against those who were involved in allegedly fixing the outcome of domestic matches in Thailand.
The FAT and the Royal Thai Police used information from data service company Sportradar as part of the investigation, following reports of an unusual number of goals being scored in the late stages of the games.
In his letter to FAT president Somyot Poompunmuang, Shaikh Salman wrote: "FA Thailand, with its recent actions, has sent a strong signal to all criminal elements that their actions will be contested with full force.
"I congratulate FA Thailand for taking a firm stand against the menace of match-fixing and am more confident than ever before that our dedicated and joint efforts, together with law enforcement agencies, can bring this scourge to an end."
The AFC has a zero-tolerance approach against those who attempt to manipulate matches in Asia and supports the strongest possible retribution against those who have been found guilty.
The AFC chief added: "I assure FA Thailand of the AFC's full support in the fight to protect the integrity of football."