When the House select committee investigating the January 6 Capitol attack on Thursday got to the witness testimony at its inaugural hearing, it heard from an individual with first-hand knowledge about how the far-right Proud Boys group came to storm the Capitol.

The panel’s star witness, Nick Quested, is an Emmy award-winning British documentary film-maker who founded the indie film company Goldcrest and embedded with the Proud Boys in the weeks after Donald Trump lost the 2020 election as part of a project about division in America.

“We chose the Proud Boys because they’ve been so vociferous in rallies and protests around America, and they’ve emerged as a political voice and force, particularly in the summer of 2020,” Quested told the Guardian. “We felt they were a group worth following.”

Quested spent much of the post-2020 election period following around the Proud Boys and is considered by the select committee as an accidental witness to the group’s activities and likely conversations about planning to storm the Capitol on January 6.

The documentary film-maker shot footage of some of the most crucial moments connected to the attack, starting with rallies in November and December 2020 which the Proud Boys attended alongside other militia groups including the Oath Keepers and the 1st Amendment Praetorian.

Quested then managed to capture on camera a late-night rendezvous between Enrique Tarrio, the leader of the Proud Boys and Stewart Rhodes, the leader of the Oath Keepers, in an underground parking garage near the Capitol the day before January 6.

The US justice department has referenced that encounter in indictments for seditious conspiracy against Rhodes and other militia group members, though Quested has told the select committee he does not believe that was a meeting to coordinate storming the Capitol.

Quested also filmed the Proud Boys marching up the National Mall from the Save America rally at the Ellipse to the Peace Monument at the foot of Capitol Hill, where the group’s members found themselves stopped from moving further by the edge of the US Capitol police perimeter.

Over several tense minutes, he photographed Joseph Biggs, one of the Proud Boys indicted for seditious conspiracy, having a brief exchange with another man in the crowd, who then confronted Capitol police in a moment widely seen as the tipping point of the riot.

The confrontation sparked the crowd to overturn the police barricade – despite Quested holding on to the fencing to keep it upright – and Quested filmed the charge up Capitol Hill towards the inaugural platform on the west side of the Capitol building.

“Why did I go over to the barriers in the first place? Look, there’s two types of people in this world. There’s people who walk to disturbances and people who walk away. I walk towards disturbances,” Quested said.

“I didn’t know there was a confrontation happening. I felt a disturbance in the crowd and I moved towards that confrontation. And that confrontation happened to be Ryan Samsel shaking the barriers. And then the weight of the crowd overwhelmed the officers at the barrier.”

Late in the day on January 6, Quested filmed Tarrio’s reaction to news about the Capitol attack in real time, having gone to see Tarrio in Baltimore, Maryland, where he had retreated after being ordered out of Washington by a local judge the day before.

Quested discussed his footage and more at the select committee’s inaugural hearing pursuant to a subpoena, having already testified on multiple occasions behind closed doors about his recollections and experiences around the Proud Boys on January 6.

The documentary film-maker – originally from west London and educated at St Paul’s school in London – followed the Proud Boys in the post-election period after covering conflict zones including Afghanistan, Iraq, El Salvador, Mexico, Nicaragua and Syria.

Among other works, Quested produced Restrepo, the 2010 Oscar-nominated film that followed a platoon in Afghanistan for a year, and directed the 2018 duPont-Columbia award-winning film Hell on Earth, as well as more than 100 hip-hop videos, including with Dr Dre.