SINGAPORE—A spate of police investigations and alleged accounting irregularities among companies is denting investors’ confidence in this financial hub, forcing the country’s stock exchange to address what critics say is a legacy of weak corporate governance and market regulation.
The tightly-run city-state has historically presented a clean image to global investors. But problems have arisen in recent years, even among some government-linked companies that were standard bearers for the local market. An “old boy’s club” of...