A New York Times reporter is expected to reluctantly testify in a trial run to see what evidence he could offer in the case of a former CIA officer accused of leaking classified information.

Federal prosecutors have said journalist James Risen is a critical witness in a case against ex-CIA employee Jeffrey Sterling. Prosecutors believe Sterling was a source for a book by Risen that detailed a botched effort to cripple Iran�s nuclear program.

A judge ordered Monday�s hearing in northern Virginia to work out in advance any snags in calling Risen to the stand.

Risen has said that to protect his sources� confidentiality, he will refuse to answer detailed questions.

Prosecutors have subpoenaed Risen but promised to limit their questioning. Defense attorneys may also want to question him.

(AP)