Two Korean cases involve payment accounts and 17 betting sites, while Taiwanese authorities described a separate tea-shop operation spanning Taiwan and Cambodia.
Joint inspections will target unauthorized online gambling at licensed casinos.
Union members continue to seek reinstatement and renewed negotiations with the casino operator.
NagaCorp recorded lower gaming revenue as its VIP segments declined sharply.
Cambodia has ended online gambling and betting nationwide, with the government saying the sector will not be reopened and authorities stepping up enforcement against violations.
Prime Minister Hun Manet says the Government has no plans to reopen the online gambling sector.
Prime Minister Hun Manet said casino projects will face a minimum $100m investment requirement as authorities reassess the number of gaming venues operating across Cambodia.
Authorities have also suspended nine casino licenses, frozen more than $300m in bank accounts and announced a nationwide suspension of casino-linked online gambling from October.
Regulator prepares new evaluation standards as Government tightens oversight of the gambling sector.
Authorities seize equipment and arrest two suspects during raids in Vientiane Capital.