Valeant Pharmaceuticals International Inc. said that it is under investigation by the U.S. Securities and Exchange Commission in a previously undisclosed probe, Bloomberg News reported yesterday. The drugmaker said that it received a subpoena from the SEC in the fourth quarter and would have disclosed it in due course in its 10-K filing, which has been delayed. It didn’t provide further details on the probe. The SEC probe is separate from an existing investigation into a company purchased by Valeant last year, Salix Pharmaceuticals Ltd., which was previously disclosed. The stock fell 18 percent to $65.80 at the close in New York. Valeant has lost almost three-quarters of its value since August as scrutiny on its drug price increases, distribution system and accounting intensified.