The Department of Justice has issued Merck & Co a subpoena seeking information about the drugmaker's marketing of three drugs acquired in its 2009 merger with Schering-Plough Corp.

The subpoena, which Merck disclosed in its quarterly securities filing, involves the brain cancer drug Temodar, hepatitis C medicine Peg-Intron, and Intron A, which is approved for hepatitis C as well as for forms of cancer.

The subpoena seeks information from January 2004 to the present in a federal health care investigation under criminal statutes, Merck said in its filing. The company said it is cooperating with the probe.

(Reporting by Lewis Krauskopf, editing by Gerald E. McCormick)