Sri Lanka's government on Monday hailed the awarding of Cannes' top prize to a film highlighting the plight of the Tamil minority during the island's civil war, saying authorities were working to redress past injustices.

"Dheepan", a French movie about a former Sri Lankan soldier's struggles in a French ghetto after fleeing the separatist war, captured the Cannes Film Festival's Palme d'Or prize on Sunday.

Sri Lankan government spokesman Rajitha Senaratne said the award could draw international attention to the new administration's efforts at reconcilation with Tamils following the war that ended in 2009.

"The movie talks about a situation (in Sri Lanka) decades ago. It is not the current picture. It is very different now," Senaratne, who is also the health minister, told AFP.

"We have a new government which is serious about reconciliation, ensuring justice and addressing the problems of the minorities."

Senaratne said the movie touched on the use of child soldiers during the war by Tamil Tiger rebels who were known for their suicide bombings.

"I am glad that the Tigers' use of child soldiers has come to light," Senaratne said. "With the publicity from this movie, I expect more interest in our reconciliation efforts."

The film's lead actor, Antonythasan Jesuthasan, himself a former Tamil Tiger child soldier who escaped the fighting and secured asylum in France over two decades ago, has said his character, Dheepan, was about "50 percent" autobiographical.

The Tigers, who are still outlawed by most Western nations, were crushed in a major military offensive that ended in May 2009.

But the rout sparked allegations that thousands of mainly Tamil civilians were killed or went missing.

At elections in January, President Maithripala Sirisena unseated strongman Mahinda Rajapakse, who drew international condemnation for his refusal to investigate the alleged abuses.

Since coming to power, Sirisena has lifted bans on at least two local film productions based on civilians caught up in the conflict.

During his decade-long rule, Rajapakse had branded war-themed local productions "unpatriotic" because they allegedly portrayed security forces in a poor light.