A new film stars Judi Dench as an Irish woman looking for the son that was taken from her and sold by nuns.

"Philomena", which is based on the 2009 book "The Lost Child of Philomena Lee" by Martin Sixsmith, debuted at the Venice film festival on Saturday night reports Reuters.

"I'm very keen that the Pope should see it," said the film's director Stephen Frears.

Sixsmith's book prompted thousands of adopted Irish children and their mothers to come forward and recount their experiences.

Philomena, who was put to work in a Catholic laundry after giving birth to her son out of wedlock in 1952, has her child taken away from her but she holds fast to her faith and her religion. Years later, she travels to America with the cynical journalist Sixsmith, played by co-writer Steve Coogan in the film.

In 2002, Sixsmith lost his job as a "British government spin doctor" over a controversial email that allegedly said September 11 was a good day to bury bad news.

The faithful Philomena and the world-weary journal make for an unlikely pair. Frears describes the tale as "an odd-couple film, an extraordinary road trip."

"The real Philomena's faith I found very affecting, but my heart is much more with the cynical journalist," Frears said.