Raksagecha Chaechai admits the Office of the Ombudsman is increasingly viewed as a channel to make complaints with the Constitutional Court, but denies he is working as a "postman" for quarreling politicians.
The Ombudsman secretary-general insisted he and his colleagues consider each complaint carefully before deciding whether to take further action.
The case of Prime Minister Prayut Chan-o-cha, who failed to recite the full oath of office during the cabinet swearing-in ceremony in July, proves this, he says.
Late last month, his office decided to forward a complaint against the premier to the court, which set Sept 18 to rule on whether Gen Prayut was qualified to become prime minister following his oath blunder.
The Ombudsman rejected various big names who wanted the office to push ahead with their complaints, but accepted one made by a student as it sounded most sensible in terms of law, he said.
Gen Prayut failed to recite the final sentence of Section 161 of the constitution, which requires the oath-taker to uphold and abide by the constitution. His act was viewed by Panupong Churak, a Ramkhamhaeng University student, as violating the people's rights under Section 213 of the constitution.
Mr Panupong claimed the incomplete oath could nullify the Prayut cabinet's formation as well as the government's statements and policies, affecting the government's ability to work for the people's benefit.
Similar complaints filed by activists -- including Srisuwan Janya, secretary-general of the Association to Protect the Thai Constitution -- were discarded as their accusations focused on the oath's actual recitation, which, in the Ombudsman's view, did not come under the law.
The Ombudsman also chose not to forward a complaint lodged by Seri Ruam Thai Party leader Sereepisuth Temeeyaves, who also questioned the validity of Gen Prayut's appointment as prime minister, he said.
"We are not 'postmen' who, upon receiving complaints, are bound to forward them all," Mr Raksagecha said.
The 2017 charter designates the Office of the Ombudsman as a "passageway" linking complainers, mostly politicians, with the court.
However, Mr Raksagecha said, this does not mean he has to believe all their words -- no matter whether they come from high-profile public figures or society's underdogs -- as complaints can be mixed with biased feelings. As such, he continued, the only thing the authorities can put their trust in is facts.
"That's the problem in our country -- many people don't tell the truth or reveal only parts of it," he said. "So the most desired character of Ombudsman is the ability to help the society maintain justice."
The 59-year-old has held this mindset since his school days.
In 1976, Cha -- as Mr Raksagecha is known among his friends -- gave money to one of his school teachers who offered to hold extra tutorial classes. When the teacher failed to hold the classes but held on to the money, Cha and his friends were not afraid to claim their money back, even though the teacher was known to be a "tough guy".
When he was pursuing his Master's degree in development economics at the National Institute of Development Administration (Nida), Mr Raksagecha faced another injustice that he simply could not let go.
"A librarian unfairly reserved some reading materials for several students during the examination period," he told the Bangkok Post.
"Other students tried to take out the books, but the librarian held on to them because they were reserved for students whom the librarian played tennis with."
When Mr Raksagecha confronted the librarian, a noisy quarrel followed and the problem became known to Nida's rector.
"My father always taught me to fight in the face of injustice," he recalled.
When he had the chance to work as an ombudsman, Mr Raksagecha said he told himself that ensuring fairness and justice would be his number one priority.
"When people from rural villages file complaints, I can understand how they feel because I too had experienced injustice," said the Phetchaburi native, before adding his experience of growing up in the countryside has helped him to deal with complaints filed by those living in the periphery.
"I'm also an upcountry man, I know their way of life," he said. "This makes them feel at ease when they talk to me."
The Ombudsman must stand firm in its duty to equally treat all parties, not in order to play safe and protect its image, but to clarify what is right and wrong in the society, he said.
"A case may be in line with the law, but if we can see the outcome is unjust, then a correction is in order," Mr Raksagecha said.