The Securities and Exchange Commission, the Office of the Comptroller of the Currency and other Treasury Department offices are digging into whether the New York-based bank has done enough to investigate the identities of risky clients, the Wall Street Journal wrote, citing unidentified people familiar with the matter. The Federal Reserve was already known to be looking into those controls last year.

The stock fell 5.3% to $86.84 during regular trading in New York on Thursday, its biggest drop since mid-October. A Morgan Stanley spokesperson declined to comment.

The SEC and the Treasury’s Financial Crimes Enforcement Network have sought information on certain clients outside the U.S. who’ve raised red flags and the bank’s policies to address it, the Journal said. Specifically, the SEC pressed Morgan Stanley about why it did business with some who had been cut off by E*Trade, the digital-trading platform the company acquired.

The inquiries, which haven’t been publicly disclosed by the bank, focus on a wealth management arm that has swelled into Morgan Stanley’s biggest business, generating almost half of the company’s revenue last year. The U.S. government has been ramping up pressure on the industry to tighten money-laundering controls as authorities make greater use of sanctions.

The bank has told regulators it’s improving controls and procedures and met with Federal Reserve officials to allay concerns last year.

The OCC also sent the firm a formal warning last year, known as a matter requiring attention, demanding executives address its concerns, according to the Journal. That followed an annual exam of the bank’s anti-money-laundering programs, and a document shows the bank sent the regulator detailed plans for action, the publication said.

Regulators have issued MRAs with greater frequency in recent years. When concerns are deemed more urgent, they also issue matters requiring immediate attention. Such notices are typically flagged to the board and generate a reply including a time line for corrective action. Deeper investigation or enforcement action may follow if officials are dissatisfied.