Pol Maj Gen Noppasin Poonsawat, deputy commissioner of the Metropolitan Police Bureau, revealed that the four Chinese nationals were apprehended on March 29 for unlawfully removing 32 files of documents from the rear of the State Audit Office (SAO) building without permission, according to The Nation.
During the 7.7-magnitude earthquake in neighboring Myanmar on March 28, the unfinished building in the Thai capital collapsed within seconds, killing at least 13 people and leaving 74 missing as of Tuesday, most of whom were workers.
After the earthquake, Bangkok authorities declared the area around the building a disaster zone, prohibiting unauthorized access.
However, by March 29, police received information that some individuals were removing documents from the site.
Police tracked down the first Chinese man who claimed to be a project manager with a valid work permit, employed by the contractor for the building.
The other three men were caught carrying the 32 documents, which were subsequently confiscated.
Deputy Bangkok police chief Noppasin stated that the seized files contained various documents, including details about contractors and subcontractors.
The four individuals claimed they were employees of a subcontractor working for a contractor under Italian-Thai Development Plc and had entered the site to retrieve documents for insurance purposes, as reported by Bangkok Post.
The building, constructed by a joint venture between Italian-Thai Development Plc and China Railway No. 10 Engineering Group, cost more than 2 billion baht (US$58 million). It was slated to become the headquarters of the Thai State Audit Office.
Thai authorities confirmed the building was the only one to collapse during the earthquake on March 28, while numerous high-rise buildings elsewhere in Bangkok were left unscathed, raising concerns about the construction quality of the project.
The collapse is the worst damage inflicted in Thailand by the quake, which had caused at least 2,000 deaths in Myanmar and 20 in Thailand.
Thai Prime Minister Paetongtarn Shinawatra expressed concerns over the building's quality on Saturday.
"I have questions in my mind," she said. "What happened from the beginning since it was designed? How was this design approved? This was not the first building in the country. We have to investigate where the mistake happened," she said, as cited by AFP.
Paetongtarn has ordered a probe into the incident involving a group of experts who are expected to report back to her this week.