The directors of Avengers: Endgame have pleaded with fans not to spoil the movie by giving away the storylines after reports that some scenes had leaked online.

Joe and Anthony Russo posted an open letter on Twitter addressing "the greatest fans in the world" and asked their followers not to share spoilers.

They wrote, "Please know that the two of us, along with everyone involved in Endgame, have worked tirelessly for the last three years with the sole intention of delivering a surprising and emotionally powerful conclusion to the Infinity Saga.

"Because so many of you have invested your time, your hearts and your souls into these stories, we're once again asking for your help.

"When you see Endgame in the coming weeks, please don't spoil it for others, the same way you wouldn't want it spoiled for you."

The upcoming Avengers: Endgame marks the conclusion of "an unprecedented narrative mosaic spanning eleven years and eleven franchises", the Russo Brothers said in their letter.

A trailer released in March showed the superheroes gearing up to do whatever it takes to save the world from Thanos.

Avengers: Endgame arrives in cinemas in Ireland on April 26.