Sigrid Thornton has joined the cast of Wentworth Season 4, which will premiere on Foxtel in 2016.
Thornton is the first actress to have starred in the original Prisoner series to join the cast of Wentworth.
However, rather than reprising her previous character Ros Coulson, she enters the prison as Sonia Stevens – a new character partially inspired by one originally played by Tina Bursill.
Thornton plays a wealthy but self-made dynamo behind a cosmetics empire.
She comes into the prison on remand, suspected of the murder of a missing woman.
Foxtel head of drama Penny Win said the fourth season continued the series’ finely-honed evolution as a world class contemporary drama which proudly forges its own path.
“Having Sigrid Thornton sign on to return behind the walls of Wentworth is a casting dream and a wonderful acknowledgement of the work the writing team has put into the creation of Sonia Stevens and our plans for her and all our characters,” she said.
FremantleMedia Australia director of drama, Jo Porter, said Sigrid was always on the top of the casting wish list.
"From the second Sonia Stevens steps from the brawler, there is an unsettling sense all is not as it may seem," she said.
"I am sure audiences will relish watching Sonia's long game play out across season four.”
Wentworth’s cast and crew have been shooting the new 12 episode season in Melbourne since August.
The story will resume on air next year as Bea and her cell-block mates are returning to Wentworth after the fire and rebuilding of H Block to find a new dynamic in play with a new contender for Top Dog.
On the outside, Franky is trying hard to be a productive member of society. As always, no-one should underestimate “the Freak”.
The cast includes Danielle Cormack (Bea Smith), Pamela Rabe (Joan Ferguson), Kate Atkinson (Vera Bennett), Nicole da Silva (Franky Doyle), Celia Ireland (Liz Birdsworth), Shareena Clanton (Doreen Anderson), Katrina Milosevic (Sue “Boomer” Jenkins), Robbie Magasiva (Will Jackson), Socratis Otto (Maxine Conway), Tammy MacIntosh (Kaz Proctor), Libby Tanner (Bridget Westfall), Jacquie Brennan (Linda Miles) and in the course of the season introduces Kate Jenkinson (Allie Novak), Bernard Curry (Jake Stewart) and Sigrid Thornton (Sonia Stevens).
Wentworth is a FremantleMedia Australia production for Foxtel with Porter and Win as executive producers.
Pino Amenta is series producer for season four.
The directors are Kevin Carlin, Steve Jodrell, Jet Wilkinson and Adrian Russell Wills.
The writers are John Ridley, Pete McTighe, Michael Lucas, Sam Winston and Marcia Gardner, who is both script producer and writer.
Wentworth’s third season has garnered two nominations for The 5th AACTA Awards to be held on December 9 – Best Television Drama Series and Best Lead Actress in a Television Drama for Pamela Rabe.
Wentworth is distributed by FremantleMedia International and has been sold to 87 countries.