Washington DC - Issuing a subpoena to former President Donald Trump would create a "circus" – but that doesn’t mean it won’t happen, a Republican on the select House committee on the January 6 attack on the US Capitol said Sunday.

"I don’t know. I think if I had that answer now, I’d probably go in and not be able to see all the pieces," Representative Adam Kinzinger of Illinois said when asked on CNN’s State of the Union if the investigation could be thorough without subpoenaing Trump.

"If we subpoena all of a sudden the former president, we know that’s going to become kind of a circus, so that’s not necessarily something we want to do up front," he continued. "But if he has pieces of information we need, we certainly will."

The committee investigating the deadly January 6 attack on the Capitol – in which Trump supporters stormed Congress as lawmakers met to certify the 2020 presidential election results – has issued two rounds of subpoenas so far.

Marjorie Taylor Greene Marjorie Taylor Greene threatens to expose GOP cover-ups if Matt Gaetz is opposed: "Let's all dance"

They’ve focused on planners of the rally leading up to the attack, along with former Trump aides and officials.

Trump has sought to claim executive privilege to keep information from the committee. Former White House strategist Steve Bannon cited that privilege in refusing to comply with a subpoena.

Last week, President Joe Biden said he hopes the committee "goes after" people who defy subpoenas and holds "them accountable criminally."

That comment was fine with Kinzinger.

"The president has every right to signal," he said Sunday. "I think he has every right to make it clear where the administration stands. God knows the prior administration every two hours was trying to signal to the Justice Department."