Manas Kongpaen was convicted of several offenses involving trafficking and taking bribes in the case involving migrants from Myanmar and Bangladesh.

A Thai army general was one of dozens of people convicted in a major human trafficking trial that included 103 defendants accused of involvement in a modern-day slavery trade.

Lt. Gen. Manas Kongpaen was convicted of several offenses Wednesday involving trafficking and taking bribes in the case involving migrants from Myanmar and Bangladesh. He was sentenced to 27 years in prison.

At least one other defendant considered a kingpin in the illegal trade, Pajjuban Aungkachotephan, was also found guilty. He was a prominent businessman and former politician in the southern province of Satun. He received 75 years in prison.

All the defendants were charged with human trafficking and had pleaded not guilty.

They were arrested in 2015 after 36 bodies were discovered in shallow graves in southern Thailand in what had served as holding camps until migrants could be smuggled over the border into Malaysia, the intended destination for most. Other such camps with scores more bodies were found, some on the Malaysian side of the frontier.

Migrants as slaves

According to investigators, smugglers held Rohingya Muslims fleeing persecution and poverty in Myanmar for ransom in the jungle camps until relatives could pay for their release. In some cases, they were sold to work as virtual slaves in Thailand. Poor Bangladeshis were also among the migrants.

Others did not make it as far as Thai shores. Most Rohingya were “boat people” who fled from Myanmar or neighboring Bangladesh on rickety vessels with no supplies, often to find themselves pushed back into the open sea by countries such as Thailand unwilling to welcome them.

The case drew special attention when its lead police investigator, Maj. Gen. Paween Pongsirin, fled to Australia and said he feared for his life after his findings implicated “influential people” in Thailand who wanted to silence him.

“Today’s verdict is a major step in efforts to combat human trafficking in Thailand,” said Sunai Phasuk, a researcher for the group Human Rights Watch. “Now that we see the conviction of a senior army general, local politicians, influential tycoons, and ... others complicit in trafficking of Rohingya, this should send a strong message that regardless of their status and affiliation, no one is above the law.”

In a separate case in 2015, labor abuses in the Thai seafood industry gained in prominence around the globe after a two-year investigation by The Associated Press led to the freeing of more than 2,000 slaves and the arrest of more than a dozen alleged traffickers. Several have been convicted.

The people smuggling cases that year put a spotlight on Thailand’s long history of negligence toward human trafficking cases, which led to the U.S. State Department’s demotion of Thailand in 2015 to the lowest tier in its annual report ranking countries based on their efforts to counter modern day slavery.

Since then, Thailand’s military government has repeatedly said it is stepping up efforts to tackle the problem. It labeled the fight against people smuggling a priority and introduced tougher punishments for traffickers including life imprisonment.

The Thai government’s efforts were acknowledged by the U.S., which has since promoted Thailand up a level to its current ranking on the “tier 2 watch list,” for governments that do not fully meet the minimum standards of combating trafficking but are making significant efforts to do so.

Ahead of the trial, the human rights group Fortify Rights called on Thailand to “ensure perpetrators and accomplices involved in trafficking Rohingya refugees and Bangladeshi nationals are held to account.”

“While the trial marks an unprecedented effort by Thai authorities to hold perpetrators of human trafficking accountable, the trial was beset by unchecked threats against witnesses, interpreters, and police investigators,” the group said in a statement.

“This may be the end of an important and unprecedented trial, but it’s been a rocky road, and it’s not ‘case-closed’ for survivors of human trafficking here,” said Amy Smith, the group’s executive director.