Trump morally unfit to be prez, causing damage to US: Ex-FBI chief Comey

Donald Trump is "morally unfit" to be president, former FBI chief James Comey asserted on Monday as he claimed "it's possible" that Russia may have some information on him that Moscow could use to compromise him.

Comey, 57, who was unceremoniously fired by the US president in May last year, in a wide-ranging interview to ABC News warned that "The foundation of this country is in jeopardy when we stop measuring our leaders against that central value of the truth."

He also cautioned that if Trump ever tries to sack special counsel Robert Mueller, then it would be his "most serious attack yet on the rule of law" and causing "tremendous damage" to the country's institutions.

Mueller is investigating alleged Russian interference in the 2016 US election and any potential ties between Trump campaign and Russia. Trump has repeatedly called the investigation a witch hunt and denied any collusion.

Comey led the federal probe into Russian interference in the 2016 election before he was fired by Trump