“JOY,” Sudabeh Mortezai’s drama tackling the vicious cycle of sex trafficking in modern Europe, has won the top prize at the BFI London Film Festival.

The film — following a young Nigerian woman who works the streets to pay off debts to her exploiter Madame, while supporting her family in Nigeria and hoping for a better life for her young daughter in Vienna — was named best film in the festival’s official competition Saturday.

“‘Joy’ is a provocative and unique film offering a devastating portrait of human resilience in the most inhuman of environments,” said jury head and “Room” director Lenny Abrahamson. “A raw, fresh view on sex trafficking with a sharp feminist perspective sewn in throughout — director Sudabeh Mortezai successfully immerses us in the women’s lives with her documentarist approach exploring the traps of abuse and extortion without ever becoming exploitative itself.”

The official competition jury — which included Emilia Clarke, Dominic Cooper and Andrea Riseborough — also handed a special commendation to “Birds of Passage,” directed by Cristina Gallego and Ciro Guerra.

Elsewhere, Lukas Dhont’s “Girl” added to its Camera d’Or and Queer Palm wins in Cannes with the Sutherland Award in the first feature competition, while “What You Gonna Do When the World’s On Fire” by Roberto Minervini took home the Grierson award in the documentary competition. Charlie Lyne’s “Lasting Marks” won the short film award.

This year, the festival announced the winners before each film was given a secret screening, rather than holding an awards ceremony.

“After much jury deliberation, our wonderful juries have selected four extraordinary films which encourage dialogue and understanding around issues of race, class, gender and sexuality,” said festival artistic director Tricia Tuttle.

The London Film Festival draws to a close Sunday with the world premiere of “Stan & Ollie.”(SD-Agencies)