The cast of Game of Thrones has signed contracts for a potential seventh season of the hit fantasy drama, insider reports have confirmed.

Leading actors who were on board for six series have completed renegotiations that will see their current contracts extended, should the show continue.

US network HBO has offered its principal cast members "huge raises" for seasons five and six that will make them some of the highest-paid actors on cable television, according to The Hollywood Reporter.

Based on George RR Martin's bestselling A Song of Ice and Fire novels, Game of Thrones was renewed for two further seasons in April.

While a seventh run has yet to be confirmed, the show's massive ratings success makes it a strong possibility.

Game of Thrones season 5 cast Show all 9 1 /9 Game of Thrones season 5 cast Game of Thrones season 5 cast Game of Thrones season 5 Oscar-nominated New Zealand actress Keisha Castle-Hughes will play the fiery Obara Sand, one of Prince Oberyn’s illegitimate daughters, who is seeking revenge for her father’s murder at the hands of the Mountain in season four Getty Images Game of Thrones season 5 cast Game of Thrones season 5 Nymeria “Nym” Sand will be played by Jessica Henwick, her best known role to date is in television series Silk and Spirit Warriors BBC Game of Thrones season 5 cast Game of Thrones season 5 Jonathan Pryce will star as the High Sparrow, a religious figure who could be making waves in King’s Landing Getty Images Game of Thrones season 5 cast Game of Thrones season 5 Alexander Siddig, who will be playing Doran Martell, the stoic ruler of Dorne and the older brother of the gruesomely slain Oberyn Getty Images Game of Thrones season 5 cast Game of Thrones season 5 Enzo Cilenti (left) will take on the part of the slave trader Yezzan Rex Features Game of Thrones season 5 cast Game of Thrones season 5 London-born star DeObia Oparei will play Areo Hotah, the loyal protector of Doran Martell Getty Images Game of Thrones season 5 cast Game of Thrones season 5 Rosabell Laurenti Sellers will play Tyene Sand, one of the illegitimate daughters of Oberyn Martell, the Prince of Dorne Getty Images Game of Thrones season 5 cast Game of Thrones season 5 Myrcella Baratheon will be played by newcomer Nell Tiger Free Rex Features Game of Thrones season 5 cast Game of Thrones season 5 Newcomer Toby Sebastian will take on the role of Trystane Martell, the youngest son of Doran

It is believed that a tiered system is used to pay the stars of Game of Thrones, with Peter Dinklage (Tyrion Lannister), Lena Headey (Cersei Lannister), Kit Harington (Jon Snow), Emilia Clarke (Daenerys Targaryen) and Nikolaj Coster-Waldan (Jaime Lannister) paid the most as the "A" tier.

Maisie Williams (Arya Stark), Sophie Turner (Sansa Stark) and Natalie Dormer (Margaery Tyrell) are said to be in the "B" tier but will also receive raises for the season seven option.

Despite cast members extending their contracts, their characters could be killed off at any point, meaning they would lose their jobs. George RR Martin is famous for his gruesome deaths and is yet to finish the book series.