(CNN) -- JJ Murphy, an actor who was set to join the "Game of Thrones" cast, died August 8, his agent said. He was 86. 

"I had the pleasure and honour to be his Agent for the last 18 months and have never encountered a man with more spirit, passion and love for his craft," Philip Young said in a statement. "At this time our thoughts are with his family.' 

Murphy had been cast in the role of Ser Denys Mallister, the oldest member of the Night's Watch on HBO's hit series. The Belfast Telegraph reported that the actor died just four days after filming his first scenes on "Game of Thrones." 

On Monday that show's producers, D.B. Weiss and David Benioff, expressed their condolences in a statement and said they would not be seeking another actor to replace Murphy. 

"We will not be recasting J.J. Murphy.," their statement said. "He was a lovely man, and the best Denys Mallister we could have hoped for. And now his watch is ended." 

According to a biography provided by his agent, the actor's work was well known in Northern Ireland where "Game of Thrones" films. Murphy trained at the Old Group Drama School in the 1940s and '50s, and was a member of the Arts Theatre Players Company and the early Lyric Players. 

He was active in the actors trade union and his work in support of Irish actors won him an honorary lifetime membership with the former British Actors' Equity Association. He also sponsored an orphanage in Romania. 
Why did he stop filming with them?
Murphy had been cast in the role of Ser Denys Mallister, the oldest member of the Night's Watch on HBO's hit series. The Belfast Telegraph reported that the actor died just four days after filming his first scenes on "Game of Thrones." 