Weeks before the Capitol attack, top Republican political activists Roger Stone and Ali Alexander identified the January 6 congressional certification as the final chance for Donald Trump to attempt to overturn the results of the 2020 presidential election.

The focus on the congressional certification, according to sources familiar with the matter, was one of several areas they marked as potential flash points to exploit as leaders of the Stop the Steal movement to help Trump reverse his defeat to Joe Biden.

As Stone and Alexander mounted their political operation, they allowed their activities to be recorded by two conservative filmmakers over several months starting from when they first began to strategize around the time of the election, through to January 6.

The arrangement meant the filmmakers, Jason Rink and Paul Escandon, captured fly-on-the-wall footage of Stone and Alexander as they led the Stop the Steal movement, and their interactions with top Trump allies, according to a teaser for the documentary titled The Steal.

In following Stone and Alexander, the filmmakers recorded most of the key moments in the timeline leading up to the Capitol attack, including an “occupation” of the Georgia state Capitol in November and rallies in Washington that almost seem like dry-runs for January 6.

They also caught on camera public and private moments at the events Stone or Alexander attended. Among others who appear in the documentary are the House Republican Paul Gosar, former Trump lawyer Rudy Giuliani, and Trump’s former national security advisor Michael Flynn.

At one point, the footage reviewed by the Guardian shows, Alexander appears to presage the flashpoint that would be January 6, saying of Biden: “The House and the Senate must certify the electoral college. There is no president-elect until the electoral college meets.”

Taken together, the footage gives an inside look at what Stone – the longest-serving political advisor to Trump and to whom Alexander was something of a protege – was thinking and doing as he strategized ways to make sure Biden would not be certified as president.

Stone also allowed himself to be filmed by a Danish documentary film crew that recorded his activities in his room at the Willard hotel as the Capitol attack unfolded, the Washington Post reported earlier this year.

The House January 6 select committee emailed a letter earlier in January asking to review the footage, but a lawyer for Rink declined the request, citing the need to maintain journalistic independence and fears the content would leak from the inquiry.

House investigators did not ultimately pursue the matter after the lawyer indicated he would litigate a subpoena; unless filmmakers have said they would only turn over footage in response to a subpoena, the panel has generally avoided that route.

A spokesman for the select committee declined to comment if that position had changed.

The question about the footage, however, recently resurfaced inside the select committee, days after former Trump aide Cassidy Hutchinson testified under oath that Trump ordered his then-chief of staff to call Stone on the night before the Capitol attack.

Stone has denied that the call took place, just as he has denied that he had anything to do with the events of January 6. He declined to cooperate with the select committee in an interview, asserting his Fifth Amendment right against self-incrimination.

“Any claim, assertion or implication that I knew about, was involved in or condoned any illegal event on January 6, or any other date, is categorically false and there is no evidence or witness to the contrary,” Stone has previously said.

But while the full extent of what the filmmakers recorded remains unclear, parts of the footage reviewed by the Guardian make The Steal Movie seem like a detailed account of the behind-the-scenes efforts by Stone to stop Biden from becoming president.

The activities of Stone with respect to stopping Biden’s certification is of interest to January 6 investigators since he had close ties to leaders of the far-right Proud Boys and Oath Keepers groups that stormed the Capitol and have since been indicted for seditious conspiracy.

Many of the key moments for the Stop the Steal movement, managed by Alexander but ultimately controlled by Stone, according to sources familiar with how they worked in practice, were captured on tape by Rink and Escandon’s film crew.

The filmmakers followed Stone and Alexander starting immediately after the 2020 election and tracked Stop the Steal leaders descending on multiple states to advance discredited claims of election fraud.

Several important moments in the timeline leading up to the Capitol attack are caught on camera.

The footage first shows Alexander in the Georgia state capitol in mid-November 2020, around the time that he and far-right activist Alex Jones staged an “occupation” protest of the building, in a stunt that echoed plans to “occupy” the US Capitol on January 6.

The filmmakers are then present with Stone at a rally in Washington DC on 12 December 2020, where Michael Flynn, a former Trump national security advisor-turned political operative, spoke at a Women for America First-affiliated event near the supreme court.

That event is significant because the Proud Boys were in Washington that day, and a contingent marched through the National Mall similar to how they did on January 6. The Oath Keepers, another far right group, acted as a security detail at the rally, similar again to January 6.

The filmmakers are also understood to have captured some footage the day before and the Capitol attack, including discussions between Stone and Alexander, as well as the fate of the “Stage 8” rally that Alexander had planned on January 6 yards from the Capitol.

Stone never went to the Save America rally at the Ellipse where Trump spoke, after a dispute over VIP passes, according to people familiar with the incident. He also never went to the Stage 8 rally on the East Front of the Capitol and instead left Washington in a hurry.