The charges against Alan Morison, the 67-year-old Australian editor of independent Thai news website Phuketwan
, and reporter Chutima Sidasathian, a Thai citizen, could earn them seven years in jail
-- two years on criminal defamation charges and five years for breaching the Computer Crimes Act.
The judge's verdict in the case, heard in a Phuket court, will be delivered on September 1.
The charges relate to a Phuketwan article published in July 2013.
The story included a 41-word paragraph from a Reuters investigative article
alleging that "Thai naval forces" had profited from involvement in the smuggling of ethnic Rohingya from neighboring Myanmar.
No-one from Reuters, which won a Pulitzer Prize for the series of reports on Rohingya that the article featured in, was charged over the original story.
"We are confident," that the court will vindicate them, Morison told CNN at the end of Thursday's hearing.
He said the Royal Thai Navy should have responded to the allegations by launching an investigation inside its own organization, rather than pursuing a case against journalists.
'Threat to democratic society'
The case has been slammed by press freedom organizations and human rights groups, including the U.N.'s Office of the High Commissioner for Human Rights.
Eight international rights groups signed an open letter
to Thai Prime Minister Prayuth Chan-ocha calling on him to drop the charges, claiming that the case constituted a threat to the "bedrock of Thailand's democratic society."
"The fact that these two journalists are even on trial is a scathing indictment of the Thai government's unwillingness to respect media freedom and clear indicator of how far and fast the environment for free expression has deteriorated under military rule," Human Rights Watch's Asia division deputy director Phil Robertson said in a statement.
Article 'in public interest'
Chutima told CNN that she and Morison had testified in court on Wednesday, defending the use of the paragraph that had prompted the charges.
"We explained to them that the term 'Thai naval forces' doesn't mean the Royal Thai Navy, but it means any forces with capability or resources to work in water or at sea," she said.
An English linguistic expert gave further evidence for the defense in support of their argument, she said Thursday.
A second witness, with expertise on the Computer Crimes Act, also testified in their defense Thursday, arguing that the law was intended to prevent crimes such as hacking or credit card skimming, but had been abused.
Chutima told the court that, in writing the article, she and Morison had been simply doing their jobs and acting in the public interest.
Phuketwan has halted its reporting for duration of the trial.
A statement on the website
says: "Our reporting on vital matters about Phuket and Thailand will halt for the trial of two journalists on July 14-16 and may not resume. Phuketwan's future is uncertain because of a highly controversial criminal defamation action."
The persecution of the stateless Rohingya Muslim minority in Myanmar has fueled a migrant crisis in Southeast Asia, as tens of thousands have been driven into the hands of traffickers in their attempts to flee.
The ensuring Thai crackdown saw trafficking networks abandon their human cargo at sea, leaving thousands of vulnerable migrants on rickety wooden boats ping-ponging between different countries
as they attempted to make landfall.
The crackdown led to dozens of arrests, including of a senior army officer in the region, Lieutenant General Manas Kongpan, on human trafficking charges.
Thailand's military junta, which toppled the government of Yingluck Shinawatra in a coup last year, has introduced strict controls
on media, amid a clampdown on civil liberties
Prayuth has repeatedly griped publicly about journalists, and was slammed for an offhand comment at a press conference in March that he would "probably just execute"
any reporters who stepped out of line.
Benjamin Ismail, head of the Asia-Pacific desk for Reporters Without Borders, called on the Thai government "to end their policy of harassing the media."
"The trial of these two journalists, who just did their job as news providers with a great deal of professionalism, poses a great danger to all those independent voices in Thailand who want to use their freedom of expression and information," he said in a statement