SEOUL—A merger of two Samsung affiliates in 2015 is drawing fresh scrutiny this week, wiping out billions of dollars of stock-market value and creating new headaches for South Korea’s biggest conglomerate.
On Tuesday, the country’s financial regulators issued a warning to Samsung Biologics Co., the conglomerate’s contract drug-manufacturing arm, for alleged accounting irregularities, triggering a two-day stock selloff that has erased $6 billion from the company’s market capitalization.
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