South Korea’s police have advanced a months-long inquiry into domestic use of Polymarket from investigation into formal charging. Twenty-six local participants on the crypto prediction platform have been booked on suspicion of illegal gambling, and 18 of those cases have already been sent to prosecutors.
The actual numbers come from National Police Agency material supplied to the office of Democratic Party lawmaker Yoon Kun-young and first published in Korean by Asia Economy (The Asia Business Daily). As of September 15, the Gangwon Provincial Police Agency’s cyber investigation unit had completed bookings against the 26 users.
Combined stakes attributed to the group amount to about 17.6 billion won, or roughly $12.7 million.
One person is said to have wagered about 5.7 billion won, around $4.1 million.
Polymarket is a non-custodial market where users buy and sell yes-or-no contracts on political, economic, and social events, usually with dollar stablecoins.
In the United States the service has been treated as a regulated prediction venue. Korean investigators take a narrower view.
They say putting property on an outcome the bettor cannot control satisfies gambling under Article 246 of the Criminal Act.
Police have also cited Supreme Court language treating a stake on an uncertain result as gambling even when some analysis is involved.
That reading matters because South Korea licenses only a small set of betting channels.
Sports Toto, operated by the Korea Sports Promotion Foundation, is the main legal outlet and caps an individual wager at 100,000 won.
Activity outside that system has long been treated as private gambling.
Ordinary gambling can carry a fine of up to 10 million won. Habitual gambling can bring up to three years in prison or a larger fine.
Whether prosecutors will seek the heavier charge, and whether courts will treat event contracts as distinct from casino-style chance, has not yet been tested at trial in this matter.Investigators did not start with a customer file from the platform.
Because Polymarket settles peer to peer and does not hold user funds in the usual exchange sense, there was no conventional domestic user list.
Police instead used open-source intelligence on public blockchain records to connect wallets to Korean traders.
Preliminary work reportedly began in March, with formal bookings from May, after heavy activity around the June 3 local elections drew official attention.
Access restrictions followed the criminal probe.
On August 18, 2026, the Korea Communications Standards Commission moved to block the site for users inside the country.
The commission said a winner-takes-all payoff on events beyond a participant’s control encouraged a gambling mindset and created an illegal betting environment, even if the technology is decentralized and the operator sits abroad.Referral to prosecutors is not a conviction.
The police material cited so far does not list indictments, hearing dates, or judgments.
Even so, the case is an early test of how Korean criminal law will classify crypto prediction markets: as information-bearing contracts, or as unlicensed wagers wrapped in blockchain infrastructure.
For residents, the practical point is already visible. A service that is lawful in one country can still expose users at home if local statutes define the same conduct as gambling.