Caruso, who posted the image on his Twitter page, captioned it: "Is Vin Diesel photobombing (discreetly) producer Jeff Kirschenbaum's moment with Ruby Rose and Deepika Padukone?"
The Indian actress, who is making her debut in Hollywood with the actioner, retweeted the post for her fans.
Deepika is currently shooting for the film in Toronto.
The movie has been set for release on January 20, 2017.
Diesel starred in the original 2002 "XXX", directed by Rob Cohen, as underground sports star Xander Cage, who was blackmailed by the US government to take down a gang of international terrorists.
The actor was not part of the sequel, as rapper Ice Cube played the lead role in 2005's "xXx: State of the Union".
The film will also star Nina Dobrev and Donnie Yen.
