Three rogue treasure hunters have been arrested for illegally excavating and selling hundreds of antiques in Thailand.

Thotsaphorn Rermcham, 26, his brother Thotsaphon Rermcham, 19, and Sri-on Chanthana, 46, dived into rivers and dug up archaeological sites to search for precious relics which they would advertise and sell on social media.

Conservationists reported the gang's activities to the Crime Suppression Division (CSD) and on August 28 an arrest warrant was issued for them on charges of illegal possession and sale of artifacts.

The trio was later caught during police raids in nine different locations across Chiang Mai, Phayao, Sukhothai and Lampang provinces.

Their haul was displayed at press conference on September 4.

The CSD said police posed as buyers to purchase products from the suspects, then sent the items to the Thai Fine Arts Department to verify their authenticity.

Central Investigation Bureau (CIB) chief Police Lieutenant General Jirabhop Bhuridej said: 'The findings show the items are genuine antiquities. One is an engraved cow figurine about 1,600 years old and the other an elephant figurine with a seal dating back to the 21st century.'

He said four bank accounts linked to the suspects have been frozen, while 970 artefacts and 11 metal scanners were seized.

The suspects had allegedly earned around 200,000 THB (5,640 USD) a month by selling the antiques online, and are believed to have made 10 million THB (282,150 USD) over their three years in business.

Brothers Thotsaphorn and Thotsaphon claimed they were not aware their activities were illegal. While Sri-on has denied all charges.

They were detained in police custody for violating the Act on Ancient Monuments, Antiques, Objects of Art and National Museums.

The illegal antiques trade has flourished across Thailand, which was formerly part of the spectacular Khmer empire when stunning Hindu temples filled the region.

Traders began looting temples and plundering archaeological excavations in the turmoil of the 1970s Cmabodia civil war followed by the American-backed Khmer Rouge genocide. Only in recent years have authorities begun to reclaim stolen artifacts and regulate their sale.