A former congressman who claims that American MIAs are being held prisoner 20 years after the end of the Vietnam War is now getting official U.S. attention. A Pentagon official arrived in Hanoi today to investigate the charges by Billy Hendon, a onetime Republican lawmaker from North Carolina who had briefly handcuffed himself Saturday to the gate of a U.S. office in Hanoi that deals with MIA reports. Though no U.S. official has publicly given credence to reports of MIAs still held captive, Hendon says a contact in Thailand told him an intelligence source saw the prisoners in February. He refused to disclose details, saying he wants to lead investigators to the facility himself. "I came here today to take the experts to the exact point where the Americans are being held," Hendon said. "Nothing political, purely humanitarian."