According to Entertainment Weekly British star, Ian McShane, will play a ‘mystery role’ in the series, with show bosses refusing to elaborate further.
However the publication reports that McShane’s character, while having only a small amount of screen time will be of ‘key importance’ to the show.
Production is already underway on the sixth series of the HBO show, which is likely to be aired in Spring 2016.
McShane, 72, has an acting career which spans six decades, remaining best known in the UK for the likes of Lovejoy, which ran from 1986-1994 on BBC One.
However he found fame in the US as Al Swearengen in the HBO Western series "Deadwood" , a role which netted him a Golden Globe for best actor in 2004.
More recently he starred in US drama, "Ray Donovan", currently airing on Sky Atlantic.
The actor’s big screen credits include "Sexy Beast", "Kung Fu Panda", "Pirates Of The Caribbean": On Stranger Tides and "John Wick" as well as Sacha Baron Cohen’s forthcoming Grimsby.
Source: Metro.co.UK