Comey pleaded not guilty during a brief court appearance in October before the case was dismissed in November.
US District Judge Cameron Currie tossed the indictment against Comey because of prosecutor Lindsey Halligan’s “invalid” appointment as US attorney.
Halligan, the prosecutor in eastern Virginia who secured the indictments, was not authorised to present the charges to the grand jury, the judge said. Halligan is a former White House aide who had never prosecuted a case before.
The judge, however, left the door open for the government to try again.
Comey acknowledged that possibility after the ruling, saying he believes Trump “will probably come after me again.”
Comey was fired by Trump during his first term after leading an investigation into Russian interference in the 2016 US presidential election. Since then, he has been a frequent target of the two-term US president.
Earlier on Tuesday, a separate judge ruled that former federal prosecutor Maurene Comey – James Comey’s daughter – can move forward with her case challenging her firing by the Trump administration.
