Who leaked classified US info on Indo-Pak War in 1971?

Jack Anderson, an American investigative journalist, first reported about the US tilt towards Pakistan under secret orders from then President Richard Nixon. Anderson got the Pulitzer Prize for national reporting in 1972 for his reports on US’ tilt away from India.

The United States administration had ordered a high-level inquiry into the special reports by Anderson in The Washington Post on December 14 and December 16, 1971.