Zack Snyder has hinted Lex Luthor may appear in the 'Man of Steel' sequel.

The director has begun work on a follow-up to his hit film, which will see Henry Cavill's heroic character face off against caped crusader Batman - played by Ben Affleck - and he appeared to suggest that Superman's most iconic nemesis may be in the film, too.

During a live online fan event to promote the 'Man of Steel' DVD release, he teased: ''Lex loves calling him an alien.''

The filmmaker also suggested that Superman and Batman will come to blows in the film.

He added: ''The fun of the idea is to be able to play with that relationship. Whether they fight and become friends, or whether they're friends and they fight. Of course, some physical conflicts [will be involved].''

'Man of Steel' grossed more than $600 million upon its release in June.

The sequel, which will be released in July 2015, will star both Cavill and Affleck, as well as 'Man of Steel' supporting actors Amy Adams, Laurence Fishburne and Diane Lane.