SYDNEY, June 18 (Xinhua) -- A dramatic portrayal of female interaction and class struggle has been awarded best picture at the 65th annual Sydney Film Festival.

Directed by Marcelo Martinessi, The Heiresses explores the subject of wealth in Paraguay through the story of a financially struggling relationship between two older women.

"Cinema is a collective work ... sometimes we win, and sometimes we don't win. But the important thing is to always do what we strongly believe in," Martinessi said on Sunday evening during his acceptance speech when he received the festival's 60,000-Australian-dollar (45,000-U.S. dollar) prize.

Chosen by a panel of five international judges, the South American film was highly praised for its stunning cinema art.

"What you learn from the success of the Sydney Film Festival is that there's still an audience that wants to come and see movies where they're meant to be seen - on cinema screens, where they're designed to be shown," Sydney Film Festival programmer David Stratton said.

"Not sitting at home and watching them on television, no matter how big your television screen is."

With more than 170,000 Sydneysiders attending the event on June 6, the 12-day festival featured over 300 films from 66 countries.

In other categories, Australian filmmaker Ben Lawrence was awarded best documentary for his film Ghosthunter, which follows a Western Sydney security guard and paranormal investigator on their search for his estranged father, while indigenous Australian filmmaker Warwick Thornton won the award for trail-blazing screen practitioner for his feature Sweet Country.