Tonga police are trying to track down the source of counterfeit Tonfon phone cards.
Assistant Police Commander, Kainga Hia, says most of the fake cards are being sold through shops owned by Chinese.
Tonfon Entertainment has advised the public the counterfeit phone cards are being sold openly Nuku'alofa.
A statement from the Shoreline Group of Companies says how and when the cards entered the Kingdom is yet to be determined, but Tonfon management believes the cards were brought in by ship.
Tonfon has warned the public to be careful when buying phone cards to ensure they're the genuine Tonfon cards.