Story highlights "If the President is found to have done this to circumvent this investigation, to thwart to the efforts to get the bottom of this, I think this is going to be an impeachable offense," Rep. Al Green said Tuesday.

"It just doesn't look right, it doesn't smell right," Green added.

(CNN) Democratic Rep. Al Green said Tuesday evening that President Donald Trump's firing of FBI Director James Comey would be an impeachable offense if it was done to stop the investigation into alleged ties between Russian and Trump's 2016 campaign.

Trump fired Comey Tuesday, citing a letter from the deputy attorney general that criticized the FBI director's handling of the investigation into Democratic nominee Hillary Clinton's email server. However, the timing of Comey's firing -- in the midst of an FBI investigation into Trump's associates and Russia -- has raised serious questions about the President's motives.

"Well, we live in a world where it's not enough for things to be right. They must also look right," the Texas congressman told local news station KRIV in Houston. "This doesn't look right given that we know now that the FBI is currently looking into this Russia association with the President and some of his associates. It just doesn't look right for this to happen essentially about what happened with (former acting Attorney General Sally) Yates testifying. It just doesn't look right, it doesn't smell right. This is something that we have to get to bottom of and it's starting to become something akin to an impeachable offense.

"If the President is found to have done this to circumvent this investigation, to thwart to the efforts to get the bottom of this, I think this is going to be an impeachable offense. He's really treading in some very dangerous waters. This is unusual for this kind of thing to happen in the United States of America."

Earlier in the interview, Green said there would need to be an independent commission with broad subpoena power to look into Russia ties.