Thai prosecutors have indicted 72 people, including politicians and an army general, over the trafficking of migrants from Myanmar and Bangladesh.
Arrest warrants have been issued for more than 30 others, the attorney general’s office said.
The investigation follows the discovery of mass graves, believed to contain the bodies of refugees, in jungle camps near the Thai-Malaysian border in May.
Many migrants endured arduous sea journeys before arriving in Thailand.
The suspects face charges including human trafficking, partaking in a transnational crime network, and bringing aliens into the kingdom illegally.
Most of those indicted are from Thailand, but several Myanmar and Bangladeshi citizens are also being held.
“We will not let influential people rise above justice,” said Wanchai Roujanavong, a spokesman for the attorney general’s office (OAG).
“The OAG has given priority to the issue, as it is a big group of people involving international systems. It has caused a lot of damage to the country as dead bodies were found,” he added.
The suspects include local politicians, government officials, police, and Lt Gen Manas Kongpan, who once oversaw trafficking issues in south Thailand.
Thai authorities faced international pressure earlier this year to crack down on smugglers after images of thousands of migrants from Bangladesh and Myanmar stranded at sea were shared around the world.
Migrants were also held in jungle camps under horrendous conditions while they awaited transportation elsewhere.
Mass graves were discovered in an abandoned camp in the southern province of Songkhla in May.
Thailand and Malaysia are desired destinations for members of Myanmar’s Rohingya Muslim minority and economic migrants from neighbouring Bangladesh.
An investigation by the BBC’s Jonathan Head found entire communities in Thailand had been helping the traffickers.