Robert Downey Jr to star as Marvel's Doctor Doom in Avengers ...

Robert Downey Jr is returning to the Marvel superhero world after five years - but not to the Iron Man role that launched the blockbuster franchise.

The actor will make his comeback as Dr Victor Von Doom, a prominent villain in the comic books that spawned the popular film series.

Downey Jr will appear in Avengers: Doomsday, which is due to be released in May 2026, and a further instalment titled Secret Wars a year later.

Stars joining the Marvel franchise were unveiled at the Comic Con event in San Diego.

Downey Jr appeared on stage concealed behind Doctor Doom's iconic mask and green cloak before unveiling himself to fans.

Speaking to reporters, he said: "I like playing complicated characters."

The 59-year-old was instrumental in launching the Marvel movie universe, starring in its first film Iron Man in 2008.

He last appeared in a Marvel film in 2019's Avengers: Endgame.

The American actor won an Oscar for his role in Oppenheimer earlier this year.

Marvel is set to release a further three films in 2025 before Avengers returns to big screens.

Captain America: Brave New World will see Harrison Ford replace the late William Hurt as General Thaddeus "Thunderbolt" Ross.

Florence Pugh will take on a leading role in Thunderbolts, while Pedro Pascal will make his Marvel debut in The Fantastic 4: First Steps.

Disney's Marvel movie series have generated $30bn (£23.3bn) in box office takings - the first franchise to do so - but profits have slowed in recent years.

However, the recent release of Deadpool & Wolverine, starring Ryan Reynolds and Hugh Jackman, has offered the chance of a potential revival - making $96m on its opening day on Friday.

Last year, Marvel dropped actor Jonathan Majors - who played villain Kang the Conqueror - following his conviction for assaulting his girlfriend.