The man accused of using the now famous pseudonym is 40-year-old Marcel Lazăr Lehel.
In spite of email correspondence leaked by Guccifer, Powell denies having an extramarital dalliance with a diplomat.
The same hacker who released private email from George W. Bush and Hillary Clinton has now exposed a Defense Intelligence Agency officer's emails to his girlfriend.
Neile Miller was a target in line with the main thrust of Guccifer’s hacking interests.
The notorious celebrity hacker is back to his old tricks, breaking into the email account of Christopher Kojm, chairman of the National Intelligence Council (NIC).
Previous targets of the mysterious hacker have included General Colin Powell, venture capitalist John Doerr and President George W. Bush.