Alien bodies allegedly hidden by the United States government. Suspected Pentagon cover-ups of secret spending programs. Retaliation against any official who dares speak out. Perhaps no congressional briefing offers up more titillating claims — or does less to illuminate them — than one about U.F.O.s.

On Friday, members of Congress entered such a session with burning questions, only to receive hedged answers that they said did little to demystify what the government knows about extraterrestrial beings.

The closed-door briefing with Thomas A. Monheim, the inspector general of the intelligence community, was supposed to help members of the House Oversight committee understand if there was any credibility to the bombshell claims made by a high-profile whistle-blower in July.

But what, if anything, was actually said was far from clear. It didn’t help that the whole session was confidential, so the lawmakers were barred by law from relaying what they had heard — not exactly a formula for combating the raft of conspiracy theories that has sprung up around U.F.O.s, fueled by government reports documenting unexplained incidents with what it calls “unidentified anomalous phenomena” and the recent whistle-blower account.