“Watergate,” a four-hour documentary examining the scandal that ended Richard Nixon’s presidency, had its world premiere in 2018 at the Telluride Film Festival, an event known to foretell future Oscar nominations. It went on to be shown at the New York Film Festival and several others, collecting positive reviews that highlighted allusions the series made to the Trump presidency.

It aired on the History Channel over three days in early November, just before the 2018 midterm elections. To the filmmaker’s surprise, it was never broadcast on American television again.

The writer and director of the documentary, the award-winning filmmaker Charles Ferguson, is now suing the company that owns the History Channel, A&E Networks, asserting it suppressed the dissemination of his mini-series because it was worried about potential backlash to allusions the documentary makes to the Trump White House.

In the lawsuit filed Friday in State Supreme Court in Manhattan, Mr. Ferguson accuses the company of attempting to delay the documentary until after the 2018 midterm elections because a History Channel executive feared it would offend the White House and Trump supporters.

“He was concerned about the impact of ‘Watergate’ upon ratings in ‘red states,’” the lawsuit said of the executive, Eli Lehrer, “as well as the negative reaction it would provoke among Trump supporters and the Trump administration.”

Mr. Ferguson resisted that plan, and the mini-series ultimately aired shortly before Election Day. But the filmmaker contends the documentary was given short shrift, despite acclaim in the film industry and previous assurances that it would receive “extremely prominent treatment.”

The lawsuit describes the treatment of the documentary as part of a “pattern and practice of censorship and suppression of documentary content” at A&E Networks, and cites several others that it says were subject to attempted manipulation for political or economic reasons.

A&E called the lawsuit meritless and the assertion that the documentary was suppressed “absurd,” saying its decision to not rebroadcast it additional times was based on lower than expected ratings.

In a statement, the company said it has routinely given a platform to storytellers “to present their unvarnished vision without regard for partisan politics.” It pointed to its partnership with former President Bill Clinton, formed during the Trump administration, to produce a documentary series about the American presidency and the fact that a subsidiary, Propagate, had produced the four-part docu-series “Hillary,” on the life of Hillary Clinton.