'Batgirl' directors Adil El Arbi and Bilall Fallah have told how the movie's axing is the "biggest disappointment" of their careers.

The pair helmed the unreleased DC superhero movie that was scrapped by the studio last summer due to a shift in filmmaking approach, and El Arbi admits one of the worst parts of the movie being ditched was that nobody could see Michael Keaton reprising his Batman role in their version.

He told Insider: "It’s the biggest disappointment of our careers.

"As a fanboy, just to be in the presence of Keaton as Batman, that’s just a privilege and an honour. But it’s a bittersweet feeling."

Fallah added: "I felt like a kid on set working with Keaton. I totally forgot that I was directing."

El Arbi also believes the movie should've been given a chance in theatres, because the audience is the pair's "ultimate boss".

He said: "We didn’t get the chance to show ‘Batgirl’ to the world and let the audience judge for themselves.

"Because the audience really is our ultimate boss and should be the deciders of if something is good or bad, or if something should be seen or not."

The filmmakers found it tough to watch 'The Flash' following Batgirl's axing.

El Arbi explained: "We watched it, and we were sad.

"We love director Andy Muschietti and his sister Barbara, who produced the movie. But when we watched it, we felt we could have been part of the whole thing."

However, in January, the pair admitted they would be willing to work with Warner Bros. again.

El Arbi told Variety: "We're fans of DC, and if we get the chance in the future to do something in that universe, we're never gonna say no. I mean, of course, our only condition is that the movie needs to come out."