The Underbelly: A Tale of Two Cities star checked into a private hospital in Sydney last year (10) to seek help for an undisclosed illness, following his alleged attack on former fiancee, Transformers actress Rachael Taylor.
Newton has since been discharged but is still being treated by experts.
He tells Australia's Daily Telegraph, "For the last five months I have been receiving full-time care and treatment for what specialists recently determined was a long-term and undiagnosed ailment.
"The details of the ailment are at this stage a personal and private matter. Although I have now left the Northside West Clinic I am continuing with ongoing treatment and will be for the foreseeable future.
"(I am) extremely grateful for the support I have received from friends, family and members of the public. While I understand and appreciate the media interest I respectfully ask that we are given some privacy."
Taylor broke off the engagement over the summer (10) and her lawyers later went to court in Sydney to apply for an apprehended violence order (AVO) against the star.
The papers revealed Taylor had accused Newton of several "unprovoked violent assaults" during a vacation in Europe in August (10).
A court granted a temporary order to keep the pair apart last month (Sep10) and now magistrates in Sydney have officially sanctioned the AVO, which will see Newton jailed for up to two years if he breaches the terms of the agreement.
Newton will be prevented from approaching or contacting Taylor unless it is through lawyers. He is also banned from entering buildings where she lives or works and from approaching her family.
Newton's lawyer, Christopher Murphy, confirmed his client had signed "a consent order without admissions to the complaint".
Speaking outside the Sydney court, Taylor told reporters, "I'm enormously humbled by the support that I've had. Today was a first and necessary step. I'm very happy to be spending more time in Sydney safely."
The actress broke off the engagement over the summer (10) and ordered her lawyer to go to court in her native Australia to apply for an apprehended violence order (AVO) against the star.
Taylor alleges she suffered several "unprovoked violent assaults" at the hands of the Underbelly: A Tale of Two Cities actor during a vacation in Italy in August (10).
And she reveals she turned to her female inner-circle after her ordeal in a bid to overcome the troubled relationship.
She tells Sydney's Daily Telegraph, "I'm really close to my girlfriends and close to my mother. I found the support of my girlfriends to be the most important thing."
The actress broke off the engagement over the summer (10) and just a day after Newton checked himself into rehab, Taylor's lawyers went to court in her native Australia to apply for an apprehended violence order (AVO) against the star.
In the legal documents, Taylor alleges she suffered two "gravely serious" attacks at the hands of the Underbelly: A Tale of Two Cities actor during a vacation in Italy in August (10).
The case went to court in Sydney on Wednesday (22Sep10) and lawyers representing both stars agreed to the conditions of the order, which is designed to protect Taylor.
Magistrate Lee Gilmour enforced an interim AVO and both sides will come back to court on 25 October (10) to have the order confirmed.
The Australian actress took out an apprehended violence order against the Underbelly: A Tale of Two Cities star last month (Aug10), alleging she was the victim of two "gravely serious" assaults by Newton while they were vacationing together in Rome, Italy.
Court papers showed Taylor suffered concussion, bruising and a sprained jaw during the alleged attacks, and claimed in the documents that Newton "threatened to end her life" on a number of occasions.
Now Taylor's father Nigel and mother Christine have told of their disgust at Newton's alleged behaviour - insisting they are "shocked" by the revelations.
Nigel Taylor tells the Sydney Daily Telegraph, "We're bitter, we're angry... but we can't say anything except that we love our daughter. We're tremendously proud of her and hope she's OK.
"We were shocked, totally shocked. We didn't know everything at first, and only heard the first part. Then more and more came out and it just got worse and worse.
"We're private people; not even our friends or neighbours know that she is a famous actress. We're not media savvy people so we are trying to stay out of it."
But the concerned father is convinced his daughter will pull through and insists she is already moving on: "She's a strong girl and a very high achiever. We love our daughter and we don't want to go saying anything that would harm our daughter or the legal matters. We just want to protect her. She's doing auditions because there's no point moping around. She's too strong for that."
The actress took out an apprehended violence order against the Underbelly: A Tale of Two Cities star last month (Aug10), alleging she was the victim of two "gravely serious" attacks by Newton while they were vacationing together in Rome, Italy.
Court papers show Taylor claims she suffered concussion, bruising and a sprained jaw during the alleged attacks - and the documents go on to detail the former couple's tumultuous past.
Taylor alleges Newton "threatened to end her life" on a number of occasions and she was forced to call police several times.
The actress also claims she required medical attention in Los Angeles after one attack which left her needing treatment for "scarring to her top lip, arm and knee" as well as "neck injuries" and "bruising" consistent with having her head "bashed against the floor and walls".
The papers read, "The defendant (Newton) physically, verbally and psychologically abused the applicant (Taylor) in the months of: January in NSW (New South Wales), March in Victoria, April in Victoria and South Australia and June in NSW."
Newton checked into rehab in Sydney for the second time this year (10) following the alleged Rome attack - but Taylor is still struggling to come to terms with the events leading up to their split.
Her lawyer Christine Nash says, "She's very distressed about the events and it takes a while to get over what just happened, so I don't think you could say that she'd be feeling particularly happy at the moment."
The Underbelly: A Tale of Two Cities star is currently undergoing treatment in Sydney for the second time this year (10) following an alleged bust-up with his girlfriend, Transformers star Rachael Taylor.
A day after he was admitted to the facility, the actress took out an apprehended violence order against the star, alleging she was the victim of two "gravely serious" attacks by Newton while they were vacationing together.
Newton's parents, Bert and Patti, opened up about their fears for their son on Monday's (30Aug10) edition of Australian news show A Current Affair - and revealed their son is under observation from experts who fear he may take his own life.
When asked if he has threatened to kill himself, Patti said, "Many times".
She explained, "He's the saddest I've ever heard anyone sound. He's just so sad. He knows what's happened. He knows what he's done. Hopefully, medication will help him sort it out and work out why he needs all this medical help. All Bert and I can do is be very sorry for everything that he has done to cause any hassle with anybody."
Patti also revealed she warned Taylor to be "careful" in the relationship because of Newton's behaviour.
She adds, "I told her many times that she had to be really careful and I worried about her, and I told her... a long time ago that: 'You have to be careful. He needs help. He needs medication'. And that's no excuse for what he did. I think we were all aware there was a bomb about to go off somewhere, sometime."
Newton's mother admits she has spoken with the actress since the incident that led to the split and the AVO order: "I don't think we have to say anything to Rachael. Rachael spoke to me the night she was leaving (Matthew) and she said he's very sick - very, very sick, he needs psychiatric help, and I said, 'I know, I agree'."
The Underbelly: A Tale of Two Cities star is currently undergoing treatment after checking into rehab earlier this month (Aug10) for the second time this year (10).
A day after he was admitted to the facility, the actress took out an apprehended violence order (AVO) against the star, alleging she was the victim of two "gravely serious" attacks by Newton while they were vacationing together in Rome, Italy.
But in a new interview, the troubled star's parents insist the holiday was a romantic getaway and their son proposed to Taylor during the trip.
His mother, Patti, tells Australian news show A Current Affair, "He kept ringing me from all parts of the world. Russia, London and then the last one, he said Rachael and he were in Italy - and I've just found out they were... engaged. He bought her a ring and... then everything went sour.
"His biggest problem is the fact that (his temper is) not a drug, it's not an alcohol problem as much as it's a mental health issue. He's always had a bit of a problem with his temper, even as a kid, but I do think it's accelerated. We don't know how to handle it."
Newton's father, Bert, told the show his son's bad behaviour stems from "his lifestyle in Sydney and getting in with the wrong people."
He adds, "I do love him and I do support him, but I don't support or condone any of the things that have happened. We should have seen the signs... but we didn't."
The full interview is due to air in Australia on Monday night (30Aug10).
Just one day after Newton checked into rehab in Australia for the second time this year (10), the actress has taken out an apprehended violence order (AVO) against the star.
She alleges she was the victim of two "gravely serious" attacks at the hands of the Underbelly: A Tale of Two Cities actor while they were vacationing together in Rome, Italy earlier this month (Aug10). Taylor is believed to have sustained injuries to her face and body during a public altercation in a hotel foyer in the city.
According to legal documents obtained by Sydney's Daily Telegraph, the AVO alleges the 26 year old fears "for her personal safety, well being and security following events both in Australia and while on a recent holiday in Rome, Italy.
"This action follows a series of gravely serious incidents, including and not limited to two unprovoked violent assaults, which (she claims) occurred on the 13th and 14th August, 2010, while Ms Taylor was in Rome."
A statement from Taylor reads: "After much consideration and struggle I have made this personal decision to send a clear public message that violence, threats, abuse and intimidation are not acceptable and should be dealt with by the full capacity of the law."
Newton was due to begin hosting Australia's The X Factor but pulled out on Sunday (22Aug10) to focus on his treatment.
He previously checked into a rehab centre in Melbourne in April (10) to seek help for alcohol abuse after he was accused of trashing a hotel room in the city where he was staying with Taylor.
The Underbelly: A Tale of Two Cities star checked into a private hospital in Melbourne in April (10) after he was accused of trashing a hotel room in the city where he was staying with his girlfriend, Transformers actress Rachael Taylor.
He left the centre earlier this summer (10) and subsequently opened up about his alcohol issues, describing himself as a "work in progress".
The star was due to begin hosting the Australian version of singing contest The X Factor but he's pulled out to focus on his ongoing health issues.
A statement from bosses at Australia's Seven network reads: "Matthew had a strong commitment to the program - he has tried his utmost to make it work. He has the support of his family and close circle of friends as he works his way back to full health."