The unidentified whistle-blower who filed a complaint against Donald Trump is a registered Democrat – the basis for an inspector general's claim that the person may have had an 'arguable political bias' against the sitting Republican president.

CNN reported Thursday on the unnamed CIA officer's voter registration record.

'A source familiar with the whistle-blower investigation tells me that the political bias referred to by the Intelligence Community Inspector General is that the whistleblower is a registered Democrat,' CNNs Jake Tapper said on the air. 'That is the bias.'

He also said the inspector general concluded that the whistle-blower's political offiliation didn't change the facts in his complaint.

President Donald Trump speaks to the press as he departs the White House in Washington

The Whistle-blower at the center of the Ukraine maelstrom is a registered Democrat, CNN reported Thursday

Mark Zaid, the whistle-blower's attorney, said on Twitter that his clients 'bias' was 'nothing more than ... registered Democrat.'

'Give me a break! Bias? Seriously? Most ppl are,' he added, while declining to confirm the information.

In 31 U.S. states, plus the District of Columbia, Americans identify themselves as members of specific political parties when they register to vote. The other 19 states dont require it.

If the whistle-blower is in fact registered to vote as a Democrat, then, he does not live in Virginia – one of the two states that surround D.C.

The unnamed CIA officer's lawyer responded with 'Give me a break' on Twitter

Donald Trump himself was once a registered Democrat in New York. That status didn't preclude him from voting for Republicans in general elections, but it would have restricted him to casting ballots in only Democratic primary contests.

The IG had suggested the whistle-blower, thought to have deep expertise in Ukrainian affairs, either was a Democrat or was a Republican who supported one of Trump's primary campaign opponents.

A preliminary review found ‘some indicia of an arguable political bias on the part of the Complainant in favor of a rival political candidate.' However the intelligence community inspector general also 'complaint’s allegations nonetheless appeared credible,' the report said.

Trump had a field day with the information, claiming the whistle-blower was a partisan Democrat.

A senior aide to the president subsequently argued on a Sunday morning news program that the whistle-blower was likely a 'deep state operative' with political motives intent on 'sabotaging' President Trump from within the government.

The president has launched a full-scale hunt for the whistle-blower he insists doesn't qualify for federal protection on account of the individual's admission he or she did not witness all of the activity outlined in the complaint first hand.

Federal whistle-blower protection law does not require first-hand knowledge, however, and the individual's identity remains a secret.

Trump also claims that the complaint that's based on part on his July 25 call with Ukraine's president, which the person was admittedly not on, is full of falsehoods and should be totally disregarded.

He said Thursday as he left the White House for a Florida event; 'The whistleblower never saw the conversation. He got his information, I guess, second or third hand. He wrote something that was total fiction and now, when people see that, they're not happy.'