U.S. prosecutors are focusing on Valeant Pharmaceutical’s vrx former chief executive and chief financial officer as they build a fraud case against the drugmaker, Bloomberg reported.

The case, if it is brought, is likely to focus on accounting irregularities. Valeant has faced allegations of accounting fraud in the past. The FBI is part of the investigations.

The case against Valeant could yield charges within weeks, the report said, citing people familiar with the matter.

(Related: Here’s a Timeline of the Big Valeant scandal)

Valeant‘s U.S.-listed shares tumbled 5.5% to $19.23. The company could not be immediately reached for comment.

Earlier this year Laval, Quebec-based Valeant replaced its long-time CEO Michael Pearson with Perrigo Co Plc’s CEO, Joseph Papa.