ALEXANDRIA, Va. (AP) — A federal prosecutor says the case against an ex-CIA officer charged with leaking classified documents to a reporter may not make it to trial because of potential problems with a witness.

Jeffrey Sterling of O’Fallon, Mo., worked for the CIA from 1993 to 2002. He is accused of leaking secrets about Iran to New York Times reporter James Risen.

At a pretrial hearing Friday in federal court in Alexandria, prosecutor William Welch told the judge that potential witness issues may prevent the case from proceeding to trial. He did not elaborate, and many aspects of the case remain secret.

Neither the judge nor Welch divulged the witness that posed a problem. But it seems clear that Risen, who has not cooperated with the investigation, is key to the government’s case.

Copyright 2011 The Associated Press