The Australian Underbelly star, who has been in and out of a psychiatric clinic in Sydney since he allegedly attacked then-girlfriend Rachael Taylor last year, is still remembered by some former colleagues as a polite and hard-working actor.
Director Michael Rymer, who worked with Newton on Face to Face, has credited him with helping him make the low-budget film in a very short period of time.
He told The Daily Telegraph: "Matthew brought so much filmmaker's intelligence to the role. He's a smart guy who gets it. He was late a few times but he's a total professional. Good-mannered and easy to direct because he's a director himself."
Rymer also revealed that when he shows the movie to Americans, they ask, 'Who is that guy?' and compare him to a mixture of Russell Crowe and Leonardo DiCaprio.
Face to Face playwright David Williamson has revealed that he was "bowled over by Matthew's performance" in the movie, adding: "He is talented, smart... It's quite tragic to see him embroiled in these personal problems."
Newton's lawyer Chris Murphy has also leapt to the star's defence, saying: "Don't write him off. He's leading a proper professional life and working hard, writing scripts. He's a major creative talent and there's redemption for him in making great movies. One day, everybody will be proud of him."
Various old school friends of Newton recently revealed that he felt a lot of "pressure" growing up because his dad Bert was so famous.
Watch the trailer for Face to Face below: