Zac Efron looks completely unrecognisable in trailer for Aussie thriller: 'Filming this was brutal'

Zac Efron has come a long way since the High School Musical days.

The 34-year-old actor is starring in a new survival thriller movie - and he's virtually unrecognisable in the teaser trailer.

The trailer for the Australian-made film Gold features a scruffy Efron caked in dirt and covered in injuries, lost in a huge desert landscape.

The actor shared the teaser on his Instagram page and revealed what it was like to film the movie.

"Filming this was brutal— but I love this s***," he wrote. "So proud of everyone involved and thank you to everyone who has watched so far."

Photo / Instagram

In the film, Efron plays a desert drifter who happens to find a huge gold nugget. While his partner leaves to find excavation equipment, Efron's character stays to look after the gold and endures several hardships which test him both mentally and physically.

The Baywatch star said he'd never been anywhere quite like the South Australian desert, where the movie was filmed.

"When we drove out to the location I was just blown away by the scenery and sort of feel and the vibe of the area," he said in a behind-the-scenes interview during the teaser.

"Unbelievably mesmerising. Very desolate and dry and very harsh conditions."

The actor recalled working during "massive dust storms" which ended up on the screen.

"We filmed through some of the gnarliest conditions I've ever witnessed in my life," he said.

"It showed a lot of solidarity and teamwork on behalf of the crew and our production. It was really really fun."

Director Anthony Hayes said filming during November 2020 was a "real challenge".

"It was probably the most brutal shoot I've done in 35 years. It was extraordinary."

Efron is known for his roles in rom-coms - but Hayes told The Age that he wanted to test his acting abilities by casting him in an intense role.

"It was a performance he'd never given before. It was extremes he'd never worked in before," the director told the Australian outlet. "But with A-list actors who are used to a level of comfort, you never know what's going to happen once you get into the desert. It's easy when you're just on a Zoom call."

He added, "Once Zac got out there, he was just the hardest working dude you could get. He didn't complain once."

This article was first published by the NZ Herald and is republished here with permission.