Bloomberg – Singapore has referred cases involving eight public officers to the police after reviewing property purchases by officials who worked at agencies involved in rail planning, Coordinating Minister for Public Services Chan Chun Sing told parliament on Tuesday.

The Public Service Division reviewed transactions between 2007 and 2014 involving 191 officers who worked in agencies involved in rail planning and bought properties near locations that were subsequently announced as subway stations, Chan said. Further checks are ongoing.

The review was launched after a US-based National Bureau of Economic Research working paper published in September alleged that Singapore civil servants used advance knowledge of future subway stations to make real estate purchases that generated “meaningful private gains.” The allegations have drawn scrutiny in a city-state that has long cultivated a reputation for a clean and corruption-free public service.

ALSO READ: Singapore home prices jump beyond estimates on sales flurry

The eight officers were identified for further examination, either because of the specific circumstances surrounding their purchases or because there was insufficient information to exclude their cases from further review, Chan said.

“Let me emphasize that a referral does not mean that wrongdoing has been established,” he said. “The police will look into the facts independently, and due process will be followed.”

Since the 1990s, all civil servants in Singapore have been required to declare purchases of private property and to annually disclose any non-owner-occupied properties they hold, he said. Depending on the circumstances, unauthorized use or disclosure of official information may also constitute an offense under the law, he added.

In its review, the government examined available records including on the officer’s role at the time, whether they had access to relevant non-public information, the timing and circumstances of the transaction, and other relevant information available to the government.

READ MORE: Singapore raises political salaries, MPs' monthly allowances

While the NBER working paper identified the period of concern as between 2007 to 2011, the PSD extended the review to 2014 “as a matter of prudence,” because many new railway stations locations continued to be announced in the years after 2011, said the Singaporean minister.

“Our approach is to assess the substantive claims in the paper on their merits by examining the methodology, the available evidence and, most importantly, the underlying facts,” he said. “This is why we have examined the actual officers’ transactions and available records. Where the facts disclose grounds for concern, we will refer them to the appropriate authorities.”

The NBER study’s authors wrote that the property purchases were mostly made by mid-level officials and agencies connected to rail planning one to two years before public announcements. The transactions were also carried out by the officials’ relatives, making them “consistent with information leakage,” according to the research paper.

“Singapore, widely regarded as one of the world’s least corrupt countries, provides a sharp setting to examine whether decades of successful anti-corruption enforcement can produce self-sustaining norms,” the researchers wrote. “The findings suggest that even in high-integrity societies, social norms may not be sufficiently self-sustaining to maintain a low-corruption equilibrium without continued formal enforcement.”