Adam Kinzinger, one of two Republicans on the House select committee investigating the US Capitol assault, will support subpoenas for testimony from Kevin McCarthy, the Republican minority leader, and senior members of the congressional GOP including Jim Jordan, a prominent Trump ally from Ohio.

“I would support subpoenas to anybody that can shed light” on events on 6 January, Kinzinger said on Sunday, on ABC’s This Week.

“If that’s the leader, that’s the leader; if it’s anybody that talked to the president that can provide us that information.”

He also suggested a subpoena for Donald Trump himself was unlikely, given the continuing circus around the former president and Trump’s habit of lying.

Kinzinger of Illinois and the Wyoming representative Liz Cheney are the only Republicans on the House panel, after McCarthy withdrew cooperation in reaction to Speaker Nancy Pelosi’s rejection of Jordan and Jim Banks of Indiana, because of their support for Trump’s lie that his defeat by Joe Biden was the result of electoral fraud.

Republicans in the Senate blocked an independent commission. The GOP has since attacked the House committee for not being sufficiently bipartisan. On Sunday even Susan Collins, a moderate senator from Maine who voted to impeach Trump over the Capitol attack, told CNN’s State of the Union: “I do not think it is right for the speaker to decide which Republicans should be on the committee.”

The panel held an emotional first hearing this week, with testimony from four police officers who fought rioters. All the officers asked representatives to find out who inspired and directed the riot.

One, Harry Dunn, said: “If a hitman is hired and he kills somebody, the hitman goes to jail. But not only does the hitman go to jail, the person who hired them does.

“There was an attack carried out on 6 January and a hitman sent them. I want you to get to the bottom of that.”

McCarthy and Jordan are known to have spoken to Trump on 6 January.

McCarthy’s conversation was raised in Trump’s second impeachment trial, on a charge of inciting an insurrection.

According to a Republican congresswoman, Trump answered McCarthy’s protests about the riot, around which five people died, by saying: “Well, Kevin, I guess these people were more upset about the election than you are.”

McCarthy has been evasive when questioned about the conversation.

Jordan admitted this week that he also spoke to Trump on 6 January.

Furthermore, according to a memo by a senior justice department official released by a House committee on Friday, Trump mentioned Jordan as an ally in Congress in a call on 27 December in which he told the acting attorney general to “Just say that the election was corrupt [and] leave the rest to me”.

“I want to know what the president was doing every moment of that day after he said, ‘I’m going to walk with you to the Capitol,’” Kinzinger told ABC, referring to Trump’s remarks at a rally near the White House on 6 January, before Congress was stormed.

Accounts in bestselling books say Trump primarily watched television, and had to be prodded into recording a statement saying the rioters should go home.

Kinzinger continued: “After [Alabama representative] Mo Brooks stood up and said ‘We’re gonna kick backside and take names, today’s the day that patriots take the country back from other people’, I want to know what they were doing because that’s going to be important.

“I want to know, you know if the national guard took five or six hours to get to Capitol Hill, did the president make any calls? And if [he] didn’t, why, and if he did of course then how come the national guard still takes five hours? I think had the president picked up the phone and made a call, the guard would have been there immediately.”

Asked if he would support a subpoena for Trump, he said: “We may not even have to talk to Donald Trump to get the information. There were tons of people around him. There were tons of people involved in the things that led up to 6 January.

“Obviously if you talk to the former president that’s going to have … everything associated with it so when I look at that I’m like, maybe. But I know that we’re gonna get to the information. If he has unique information that’s one thing but I think there’s a lot of people around him that knew something.”

Kinzinger is an air force veteran and national guard member and was one of a number of representatives who became emotional as they spoke to the officers who defended the Capitol and introduced video of the violence that day.

He told ABC: “This is stuff that we can’t sweep under the rug of, ‘That was a whole seven months ago, you know, history’ that some people are trying to do because it’s politically inconvenient.

“If anybody is scared of this investigation I asked you one question: What are you afraid of? I mean, even you’re afraid of being discovered of having some culpability in it, or … if you think it wasn’t a big deal, then you should allow this to go forward.

“So this is essential for history for the American people, for truth … anybody with parts of that information, with inside knowledge can probably expect to be talking to the committee.”