Their fans know them for their roles as evil queen Cersei Lannister and knight in exile Jorah Mormont in the hit fantasy series Game of Thrones.

Now actors Lena Headey and Ian Glen are pairing up again but this time they're focusing on the refugee crisis in Calais.

British film The Flood, which opens this Friday, sees the duo play immigration officers investigating an asylum seeker, played by Ivanno Jeremiah.

Headey plays a cynical officer given a high-profile asylum case, in which she must find out why Haile – a young man played by Jeremiah – is seeking asylum after his 5,000 km journey which ends with him arriving at the Calais migrant camp in France.

Glen plays her aggressive and critical boss who is under red tape pressure.

Lena Headey as evil queen Cersei in Game of Thrones. Credit: HBO

Headey is an ambassador for the International Rescue Committee and has publicised the work of the non-profit organisation, which works with refuges around the world.

Speaking to ITV News about her latest role, Headey said: ''It seems like we've just sort of shot it down and gone oh they've all stopped, they've all stopped coming over and no they're arriving every single day to the same beach that we saw the dead boy on, that's still happening."

When asked about her time visiting refugee camps in Greece and what struck her the most she said: "The suicide, depression, attempted suicide, rape, drugs.

"It's also we're forgetting a generation of children of brilliant children, who could bring so much to the world and that breaks my heart more than anything else."

Headey, who is renown for playing Cersei, said she won't miss her character in Game of Thrones.

"That was nine years, I'm good, we're good. I love her but we are divorced now."

Headey with her Game of Thrones co-star Iain Glen and Ivanno Jeremiah in The Flood. Credit: Megatopia Films.

The film's producer Luke Healy said it was three years in the making but it was important to make sure the story is told and for an audience to see it.

He told Variety: ''We were keen to show the complexity and the humanity on all sides of the story – the refugees, the immigration officers who decide their fate, the people smugglers and even the lorry drivers who transport them.

"Our hope was that the film is as a bare and honest reflection of what’s happening every day in the U.K., Europe and around the world."