China sends more people to Thailand than any other nation and tourism remains one of the few bright spots in the kingdom’s otherwise bleak economy.
But complaints have soared in recent years over dodgy tour guides and practices, particularly so-called “zero-dollar” scams.
Such schemes promise Chinese package tourists an impossibly cheap or free holiday only to pile on excessive charges once they arrive in Thailand.
Prosecutors this week charged 13 people from seven different Thai tour operators.
“They are charged with organised crime offences, joint money laundering and illegally running tourist operations without permission,” deputy national police spokesman Colonel Krissana Pattanacharoen told AFP.
Local media, citing Bangkok’s Criminal Court, said the companies made as much as $2.7 million through the scams.
Court officials did not respond to requests for comment.
In recent years China has played a major role in keeping Thailand’s tourist boom rolling.
Tourism authorities say they are on course to receive a record 32 million visitors this year, up from 30 million last year.
Nearly one third will come from China with 9.1 million expected, a 14 percent increase on the previous year.
Thailand’s junta, which has moved closer to Beijing since seizing power in 2014, is desperate to avoid any tail-off in Chinese visitor numbers.
So far tourists from Thailand’s giant regional neighbour have kept on coming despite some major setbacks.
Last year 20 people were killed, most of them ethnic Chinese tourists, when a bomb went off at a religious shrine in the centre of Bangkok.
Two ethnic Uighurs, a persecuted in minority in China, are currently on trial over the attack.
Authorities are keen to stamp out scams, aware they can do just as much to damage tourism as bombs.
“In turn we expect to receive more quality tourists coming in, not just Chinese but other nationalities too.”