Slain schoolgirl Charlise Mutten's mother spent about four weeks in an exclusive Sydney private drug rehab clinic where she boasted to fellow patients of having sex with her daughter's accused killer during an access visit.
Kallista Mutten stayed at the $20,000 a month Sydney Clinic at Bronte Beach last November just two months before her nine-year-old daughter's alleged murder on January 11 or 12.
Police allege her fiance Justin Stein, 31, murdered Charlise at his family's Wildenstein estate in the Blue Mountains and then dumped the child's remains, encased in a barrel, in bushland by the Colo River where they were found on Tuesday.
A former ice addict, Ms Mutten became engaged to Stein last year after being released from prison.
Former ice addict Kallista Mutten spent weeks in a ritzy Sydney drug rehab clinic two months before her daughter Charlise was allegedly murdered by her fiance Justin Stein
At the Sydney Clinic, which treats celebrities, Kallista Mutten boasted of her 'very wealthy' fiance Stein and proudly described how they would be getting married this year
Kallista also excitedly related to fellow patients how she had sex with Stein in the back of his ute (above) on an access visit when he drove down from the mountains to see her in rehab
Kallista Mutten (above kissing Stein) boasted how the couple had a tryst in his car near the Bronte clinic after which she returned 'excited and high' after the encounter
Late last year, she was housed in the Clinic's level two substance abuse unit and was visited by Stein, a fellow patient revealed exclusively to Daily Mail Australia.
The patient said Kallista was 'over the top' and 'very attention seeking' and repeatedly mentioned she had a 'rich fiance' who was 'very wealthy'.
She talked about her forthcoming wedding to Stein in 2022, which Ms Mutten has previously said could take place at the Mount Wilson Anglican Church, just minutes from where Charlise was allegedly murdered.
Inpatients at the Sydney Clinic - which has treated TV reality star Suzi Taylor, actress Jessica Marais, game show host Andrew O'Keefe and AFL player Ben Cousins - are allowed up to four hours of daily leave outside for walks or visits.
The fellow patient said Ms Mutten animatedly chattered about Stein visiting her, and after one visit she claimed 'they had sex in the back of the ute' and seemed 'excited and high' after the encounter.
She related that her fiance had driven 'a long distance... from the mountains to visit her' and was 'hyper' about the visit.
Kallista Mutten may have mentioned her daughter Charlise once 'in passing' but chatted often with other patients about marrying her rich fiance Justin Stein in Mt Wilson this year
A patient room inside the $20,000 a month Sydney Clinic where Kallista Mutten stayed and was visited by Justin Stein who has now been charged with Charlise Mutten's alleged murder
Kallista Mutten was housed on level two of the Sydney Clinic where inpatients are treated for substance abuse and was visited
