The film crew, directed by filmmaker Liz Garbus, has been filming inside the Times' offices since Inauguration Day in January.

The project, which has the working title The Fourth Estate, will air on the US cable channel Showtime. The extended length film will air in four parts, media reports said.

In addition to following the work of individual senior reporters, it will also take cameras into one of the most sacrosanct parts of a working newsroom: the editorial news conference.

Showtime has not officially confirmed the project.

CNN media reporter Brian Stelter, a former staffer at The New York Times, first reported filming for the documentary was underway.

Stelter's report said Showtime "anticipates intense interest in the film, given the Times' many scoops and scrapes involving the Trump presidency."

The Hollywood Reporter has described the project as "both an inside look at how the paper is covering Trump and the larger role of journalism today".

It will also explore how the label of "fake news" is "used by the current administration as a response to negative coverage," The Hollywood Reporter said.

Garbus' most recent credits are the HBO film Nothing Left Unsaid: Gloria Vanderbilt and Anderson Cooper, and the Netflix film What Happened, Miss Simone.

Both of those films made their debut at the Sundance Film Festival, suggesting a likely path for the release of The Fourth Estate, initially to festivals and later to television.

Despite claims from the White House that both The New York Times and The Washington Post are failing businesses, in fact interest in US political news has seen both titles enjoy a circulation and subscription surge.

The Fourth Estate is not the first documentary to go behind the scenes of the iconic newspaper New Yorkers refer to as "The Gray Lady".

Andrew Rossi's Page One: Inside The New York Times was released in 2011.