The Bangkok Post called for the claims by former major-general Paween Pongsirin to be investigated seriously and for him to be allowed to return safely to Thailand.
The newspaper said instead of threatening to sue Mr Paween for defamation Thai authorities should be making it a priority to crack down on human trafficking networks to "restore confidence in the much maligned law-enforcement institution and repair the damage the illegal trade has done to the nation's standing."
How Thai authorities handle Mr Paween's allegations will be a key test for the junta that toppled a democratically-elected government last year to "exercise its power and nail the influential figures who are part of the trafficking and smuggling rings," the newspaper said in an editorial.
Another newspaper, The Nation, described threats to sue Mr Paween by Thailand's National police chief Jakthip Chaijinda for defamation as a "knee jerk" reaction, saying that accusations by a senior police officer that fellow officers want him dead for exposing their corruption is a "very serious matter."
Similar comments were made in Thai language media.
The junta often seizes critics, including journalists, and takes them to military bases where they are held for so-called "attitude readjustment."
Critics are warned that if they continue opposing the generals their private assets will be seized.
The claims by Mr Paween, who plans to seek political asylum in Australia, have shattered the junta's claims that it has thwarted trafficking across its borders.
Mr Paween headed a high-profile task force created earlier this year after the discovery of mass graves in the mountains of southern Thailand.
For years Thai authorities had denied any involvement of corrupt officials in the trafficking of thousands of Rohingyas and Bangladeshis who took to boats across the Bay of Bengal to try to reach Malaysia.
Images of mass graves in the mountains of southern Thailand and starving and distressed families on boats shocked the world.
Mr Paween's taskforce exposed networks of traffickers and led to the arrest of more than 90 of people including politicians, government officials, police and a high-raking army officer.
But Mr Paween was forced to wind down his investigations in September and he was abruptly transferred to Thailand's southernmost provinces, where Muslim rebels have been waging a decade-long insurgency.
He protested that he would be killed by traffickers and senior police involved in the trade there, and quit the force rather than take up his new post.
"Human trafficking is a big network that involves lots of military, politicians and police," Mr Paween said after arriving in Melbourne.
"While I was supervising those cases I was warned all along," he said.