LONDON — As the suspected source for the biggest intelligence leak in American history faces his first hearing today, U.S. prosecutors have their eye on another prize: the man who disclosed the documents to the world.

When WikiLeaks' spectacular disclosures of U.S. secrets exploded onto the scene last year, much of Washington's anger coalesced around Julian Assange, the silver-haired globe-trotting figure whose outspoken defiance of the Pentagon and the State Department riled politicians on both sides of the aisle. Pfc. Bradley Manning, long under lock and key, hasn't attracted the same level of ire.

The pair's fates have been intertwined, however, even if the Australian-born WikiLeaks chief says he didn't know the private's name until after news of his arrest emerged in June 2010. Manning's alleged disclosures put Assange at the epicenter of a diplomatic earthquake.

Assange in turn has worked energetically to drum up support for the imprisoned soldier — all while emphasizing that the way his anti-secrecy site was set up meant he could not be sure if Manning was his source.

U.S. investigators have been scrutinizing links between the two as they explore the possibility of charging the Australian with serious crimes under U.S. law.

A Virginia grand jury is studying evidence that might link Assange to Manning, but no action has yet been taken.