Ezra Miller in a scene from "Justice League." Picture: AP/Warner Bros.

Warner Bros. has reportedly pushed back filming on the standalone movie centred on The Flash to late 2019.

Warner Bros. has reportedly pushed back filming for DC's long-in-development standalone movie centred  on The Flash, with it now expected to start filming in late 2019.

The movie didn't have a confirmed date but was expected to begin filming in March. However, the project's script is still being tweaked and the studio will not have time to finish the script in time for the original beginning of filming.

Ezra Miller - who will play the titular lead role the superhero flick - is scheduled to begin work on the third instalment of the 'Fantastic Beasts' franchise in July, causing the push back, which will likely see the Flash film's release delayed until 2021, Variety magazine reports.

John Francis Daley and Jonathan Goldstein - who wrote 2017's 'Spider-Man: Homecoming' - are directing a script written by 'King Arthur: Legend of the Sword' scribe Joby Harold.

In a previous interview, Miller admitted his standalone film will cause an "endless, headache-inducing fabric of multiversality".

He said: "What fans understand when they hear 'Flashpoint' would be almost like hearing a word like 'crisis'. We start to understand that our precious DC Universe will inevitably be torn asunder to an endless, headache-inducing fabric of multiversality. The DC hyped-Extended Multiverse, as I plan to call it. Quote me."