Gemma Ward is set to star in 'Pirates Of The Caribbean: On Stranger Tides'.

The Australian model - who had her breakthrough movie role in 2008's horror film 'The Strangers' - will play a mermaid in the fourth instalment of the swashbuckling Disney adventure.

The movie - which stars Johnny Depp as Captain Jack Sparrow alongside Geoffrey Rush, Megan Fox and Penelope Cruz - is due to start filming in Hawaii this week, though Gemma will not record her scenes until August.

The role marks a return to public life for the 22-year-old blonde beauty, who has reportedly taken a break from modelling to study acting.

A pal told Australia's Courier Mail: "Gemma's focus is definitely on acting. She's spent the past year studying the craft full time in New York."

However, Gemma admitted last year she had no plans to quit modelling for good.

She said: "I haven't quit modelling and my fans back home can expect to see me back at work modelling - and acting - in the new year."