Harald Malmgren, who served under John F. Kennedy, Lyndon Johnson, Richard Nixon and Gerald Ford, made the eyebrow-raising claim about the alleged conversation with CIA officer Richard Bissell in a viral post on X this week, reports news.com.au.

“Sixty-plus years ago I was provided highest level classifications to lead DOD (Department of Defence) work on nuclear weapons and antimissile defense,” Mr Malmgren wrote.

“Informally briefed on ‘otherworld technologies’ by CIA’s Richard Bissell (who had been in charge of Skunkworks, Area 51, Los Alamos, etc.) but sworn to secrecy.”