U.S. military investigators are reportedly faltering in their effort to prove a direct link between WikiLeaks and the alleged U.S. Army whistleblower Bradley Manning. According to NBC News, investigators have found no evidence Manning passed classified U.S. documents directly to WikiLeaks founder Julian Assange or that the two had any contact. The U.S. government has scrambled to find a direct link as part of an effort to indict Assange for prosecution. Manning is currently imprisoned at the Marine base in Quantico, Virginia, in solitary confinement. On Monday, the human rights group Amnesty International wrote the Pentagon to protest what it called Manning’s ”inhumane” treatment.