X-Men: Apocalypse director Bryan Singer has let on that the Marvel Comics character Caliban will appear in his sequel.

Singer revealed the inclusion of the mutant tracker in a set photograph released on his Instagram today (May 26).

"Shooting Caliban's place of 'business' #Xmen #XMenApocalypse," Singer hinted.

Caliban first appeared in Marvel Comics in 1981 as a member of the underground community of mutants called the Morlocks.

He was genetically altered to become one of the Horsemen of Apocalypse, and later went on to serve on various X-Men teams.

Singer is introducing a host of new mutants into his next X-Men movie, including Oscar Isaac as the megalomaniac Apocalypse, Ben Hardy as the Angel, Lana Condor as teen hero Jubilee and Olivia Munn as Psylocke.

Sophie Turner, Alexandra Shipp, Kodi Smit-McPhee and Tye Sheridan are also joining the franchise as younger versions of classic X-Men characters.

X-Men: Apocalypse opens next spring in the US and the UK.