James Ellis: Actor best known as Bert Lynch in 'Z-Cars' credited with helping Northern Irish actors succeed on the mainland

Ellis, centre, in a 1968 episode of 'Z-Cars' with Joss Ackland, left, and John Slater

James Ellis was an actor and stage director, best known for his role as Bert Lynch, the longest-serving character in the cast of Z-Cars, the popular police television drama which ran for 16 years during the 1960s and '70s. As the affable PC who rises to the rank of Inspector over the course of the series, he was the only member of the cast to appear in every one of the show's 565 episodes.

Ellis was born in Belfast in 1931, the son of a shipyard worker. He studied at the city's Methodist College, to which he won a scholarship, and Queen's University, where he read English literature and French philosophy.

He studied drama at the Old Vic in Bristol before going on to join the Ulster Group Theatre in 1952. There he played a variety of roles, culminating as the lead character, Christy Mahon, in JM Synge's The Playboy of the Western World, and soon rose to director of productions, by 1959. However, a year later, when Ellis chose to direct Over the Bridge (1960), a production which dealt with the religious divide in Northern Ireland and which the Group Theatre considered too difficult a subject, he was obliged to resign.

The current Northern Ireland Culture Minister, Carál Ní Chuilín, said, "James was a man of great character and was never afraid to tackle difficult issues as we witnessed with his direction of Over The Bridge, at a time when many believed that sectarianism, which the play addressed, was too controversial for a stage performance."

Ellis left for London, and controversy followed him. In September 1961 the BBC aired Stewart Love's Randy Dandy, starring Ellis as a ship-worker who refused to strike. The channel had to prepend a warning to the broadcast, indicating that it would be "unsuitable for people of a nervous disposition", the era's code-phrase to signal a play's overtly sexual content. But this, and his role earlier that year in Stewart Love's The Sugar Cube (1961), brought him to the attention of the producers of a new drama series, then at the planning stage.

Z-Cars was a police drama centred on the fictional town of Newtown, based on Kirkby in Merseyside. Whereas Dixon of Dock Green was a slow-placed, genteel depiction of life in the force, Z-Cars took its name from the response vehicles used by this newer breed of policeman, in pursuit of the motley band of criminals in the area.

At audition Ellis recalled that he was told his character would be a certain PC McGinty. However, "I reminded them about [the traditional Irish song] Paddy McGinty's Goat, and that villains would simply laugh at me," he said, "so they changed my name to PC Lynch." As Ellis's role developed, he was promoted from PC to Inspector, gaining recognition and popularity with audiences as his stature in the unit increased.

Throughout his career, Ellis took pride in not changing his voice for the roles which he took on. "His was the first Belfast accent that people in the UK regularly heard in their lives – ever," said James Nesbitt, who worked with Ellis. "This opened the gates for all kinds of accents after that. I have spoken to some of the actors who went across [to the mainland] and they said they looked at Jimmy Ellis and said, 'If he can do it, we can do it'."

Now working back in Northern Ireland, Ellis starred in Graham Reid's Too Soon To Talk To Billy (1982), the first in a trio of "Billy" plays, which brought the authentic voice of working-class Ulster Protestants to television audiences as part of the BBC's Play for Today series. Ellis played the bullying father, Norman Martin, alongside a young Kenneth Branagh, just out of Rada, in the title role.

Ellis experienced personal tragedy in 1988 when his son Adam was murdered while fishing on the Grand Union Canal in London. "I went berserk," Ellis later said. "I wasn't in possession of my senses. I kicked open the doors of every pub in the street shouting, 'Who knows who murdered my son?'" Another son from his first marriage, Hugo, also an actor, committed suicide in 2011 at the age of 49.

Other television roles for Ellis included parts in Ballykissangel, Doctor Who, In Sickness And In Health and Only Fools And Horses. He received an honorary doctorate in 2008 from Queen's University Belfast, in recognition for his services to the performing arts, as part of the university's centenary celebrations.

In 2009 Radio 4 broadcast a series of five translations he made of French stories from the writings of the 16th century poet Pierre de Ronsard, adapted to Irish settings. "I became interested in him because he came to Scotland as a young page," Ellis recalled, "and I have this insatiable curiosity about Scotland because Scottish history has always seemed so much more exotic to me than Irish history."

Branagh said in tribute, "James Ellis was a great inspiration to me, and many other actors from the North of Ireland. I was blessed to begin my career working with him, and I will never forget his generosity to me. He was a highly intelligent, funny, and kind man, and a tremendous actor."

James Ellis, actor, director and writer: born Belfast 15 March 1931; married 1956 Beth Ellis (marriage dissolved; one daughter, and two sons deceased), 1976 Robina (one son); died Lincoln 8 March 2014.