Los Angeles - Wolverine 3 will be an R-rated movie with a "violent" and "western tone".
The 20th Century Fox motion picture - which stars Hugh Jackman as the metal clawed Marvel superhero - will be "different" to its predecessors, 2009's 'X-Men Origins: Wolverine' and 2013's The Wolverine, and have a far more adult tone.
Fox producer Simon Kinberg confirmed rumours the movie would be R rated during promotion for fellow Marvel superhero movie X-Men: Apocalypse, revealing: "It's a very radical, bold, different Wolverine than you've ever seen in any of these movies.
"It takes place in the future, and as you and others have reported, it is an R-rated movie. It's violent; it's kind of like a western in its tone. It's just a very cool, different film."
Another rumour, which is yet to be confirmed, is that Sir Patrick Stewart will be reprising his role as Professor X opposite Jackman, 47.
Kinberg added: "I'm not sure what I'm allowed to say. But I will agree with you that Patrick Stewart was rumoured to be a part of that film."
British comic actor Stephen Merchant has been added to the increasingly impressive cast, though 20th Century Fox has remained tight-lipped about the exact nature of his role in the film.