In July, an estimated 14kgs of cocaine washed up on beaches in Vava'u.
Tongan police seized the haul and an ongoing investigation has seen 21 people charged so far including three foreigners.
At the end of August, Acting Deputy Commissioner of Tonga Police Halatoa Taufa told Matangi Tonga the recent arrests included a 49-year-old man and his 23-year-old wife from Ta'anea, Vava'u on August 23.
The couple are in police custody charged with engaging with others in the supply of illicit drugs.
