The army and police have come under heavy criticism over their failure to apprehend the soldier who claimed to have obtained the personal data of 55 million Thais, despite a court warrant for the suspect's arrest.
The delay was slammed by the Move Forward Party (MFP), which questioned why the suspect was still not in police custody after a court-approved warrant for his arrest on April 3. Police have also summoned his wife for questioning.
MFP spokesman Rangsiman Rome alluded to a cover-up on Monday, saying influential figures might be behind the hacking, which would explain the delay in apprehending the suspect.
He pleaded with national police chief Pol Gen Damrongsak Kittiprapas and the Royal Thai Police (RTP) to take legal action not only against the hacker but also against those acting behind the scenes.
He also suggested that the RTP and the government come up with practical solutions which could prevent such an incident from reoccurring.
On Friday, Chaiwut Thanakamanusorn, the Digital Economy and Society minister, and Pol Lt Gen Worawat Watnakhonbancha, chief of the Cyber Crime Investigation Bureau, held a press conference to clarify reports which claimed the suspected hacker and his wife had been detained by the police.
Mr Chaiwut said investigators are coordinating with the hacker's supervisors to bring the suspect in for questioning. While he stopped short of identifying the suspect by name, he revealed the suspect, known as "SM2 Khemarat", was an army sergeant major, second class.
"The police have to follow the correct procedure as the hacker is an active member of the military. As such, his superiors must bring him in," he said, noting authorities are still trying to determine the suspect's motive.
According to a PM's Office regulation on the arrest of military personnel wanted on an arrest warrant, police must inform the suspect's commanders of the warrant straight away, except when the suspect committed an offence in full view of the police, or the suspect tries to escape.
The suspect will then be summoned to appear at a police station. If he refuses to show up or attempts to escape, police investigators may ask military police to arrest and escort the suspect to a police station, according to the regulation.
The regulation is intended to prevent clashes between the police and the military as their personnel are allowed to bear arms.
Army spokeswoman Maj Gen Sirichan Ngathong had previously denied the army was dragging its feet on the arrest of the suspect.
The hacker had posted on BreachForums claiming he had obtained the personal information of 55 million Thais, including names, addresses and telephone numbers.
On the 9near.org website, which has been blocked by Thai authorities, the hacker threatened to release the information unless the state agency allegedly involved in the data breach contacted him by a certain deadline.
However, Gen Jira Komutpong, a former chief of the Judge Advocate-General's Department, said that the Criminal Procedure Code allows police to arrest military officers suspected of committing criminal offences without the need to obtain permission from their commanders.
"Right now, police don't have any excuse not to arrest soldiers who commit offences outside their barracks," he said.
Jade Donavanik, dean of the law faculty at Dhurakij Pundit University, also pointed out that if soldiers suspected of committing a crime are not on active duty, there is no need for police to ask their commanders for permission to proceed with an arrest.