Cambodian military police said on Tuesday they have arrested an award-winning reporter known for investigating local corruption, trafficking and online scam centres, prompting concern from a prominent human rights group and the United States.

Award-winning Cambodian investigative reporter Mech Dara is arrested in what's been described as a "retaliatory move" from the country's authoritarian rulers.

Mech Dara, who has been honoured for his coverage of human trafficking in the cyber scam industry, was reportedly detained by authorities in Cambodia on Monday. He posted images on social media that were dubbed "fake" by officials.

The authorities did not give a reason for the action, but it came after the United States punished a tycoon for what it said was his role in the scam compounds.

A Cambodian freelance reporter noted for his bold investigative reporting in a country with limited press freedom has been arrested