Ronan Keating "welled up" with tears a lot when he was filming 'Another Mother's Son' because of the powerful themes of the World War II drama.
The Boyzone singer plays Harold Le Druillenec, the only British survivor of the Bergen-Belsen concentration camp, in the movie in what is his second main film role.
The plot of the movie is based on real-life events that occurred during the German occupation of the Channel Islands and focuses on Harold's sister Louisa Gould (Jenny Seagrove) who hides an escaped Russian prisoner of war Bill (Julian Kostov) from the Nazi forces to save his life.
As tension mounts in Jersey, it becomes clear that British Prime Minister Winston Churchill will not risk an assault to recapture the British soil, and the island-community spirit begins to fray under pressures of hunger, occupation and divided loyalty as Louisa fights to preserve her family's sense of humanity and to protect the Russian boy as if he was her own.
Ronan admits the life and death reality of the true situation weighed heavily on his heart.
In an interview with the Metro newspaper, he said: "I welled up a lot filming this. It was intense. There's one train scene I found hard to shake off after leaving the set. It was very heavy and harrowing."
Although Ronan researched his role thoroughly he did not visit the site of the Bergen-Belsen concentration camp in Lower Saxony in northern Germany as he did not think he would be able to handle it.
He said: "No, I don't think I would be able to. That would stay with you."
Ronan may have scored eight number one hit singles in the UK with Boyzone and as a solo artist and sold more than 45 million albums combined across the world he has always harboured acting ambitions.
He shared: "Looking someone in the eye and reacting to what they say, this is exciting. Especially in a film like this where the other guy is wearing a Nazi uniform and he's speaking to you and there are all these things going on in your brain, it's just - wowser!"
And it's no secret that Ronan, 40, previously auditioned for a role as an elf warrior in the 'The Hobbit: An Unexpected Journey' which he didn't get but the experience spurred him on to keep trying out for parts.
He said: "[I auditioned] for Logolas' mate, and elf warrior, basically. For me, more than anything, it's getting into the audition room. A lot of casting agents and directors won't get past the fact I'm Ronan Keating, so it's about showing them what I am capable of."
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