The actor-turned-director beat 15 other finalists to claim the top prize yesterday at the world's largest short film festival, and dedicated the award to the controversial radio shock jock.

"Four words I never thought I would say: thank you Kyle Sandilands," Forsythe said on stage, accepting his award.

He said the film was specifically inspired by last year's infamous lie-detector scandal.

"I've had conversations with friends and family about that incident and I was just trying to make the film from another perspective, and that was my interpretation," he explained.

"The character's not Kyle, it's just someone who works in commercial radio."

First prize includes a return flight to Los Angeles to meet with agents, executives and industry representatives, $5,000 in cash, and thousands of dollars worth of film equipment and services.

The film also claimed the prize for best comedy.

It's Forsythe's third time in the finals of the film festival - last year he was a finalist for Being Carl Williams - and he said it's a wonderful experience to win.

"This means everything - I mean I entered when I was 16 years old for the first time," he said.

"Tropfest has been my film school over the years and I just feel so grateful to be able to keep screening films to audiences like this."

A fan of controversial subjects, his next project is a short film inspired by the NRL group sex scandal.

About 75,000 movie buffs set up camp in The Domain in Sydney to watch short films by the 16 finalists, as well as performances by Hoodoo Gurus and Whitley.

A total audience of about 150,000 watched around the country, in Sydney and satellite venues in Melbourne, Adelaide, Hobart, Canberra, Brisbane and Perth, as well as on Movie Extra.

A panel of celebrity judges, including Hollywood star Elijah Wood, Aussie actress Toni Collette, Daybreakers directors Peter and Michael Spierig and David Michod, who made Animal Kingdom, selected the winning films.

My Neighbourhood Has Been Overrun By Baboons by Cameron Edser and Michael Richards got second prize, and Last Roll of the Dice by Matthew Chuang won third place.

Earlier in the day Peter Richardson and Josh Raish took out Trop Jr, a competition for budding filmmakers 15 years and younger, with their short film Every Coin Has Two Sides.