"She was transferred from the Pretoria Central Correctional Centre to a community correctional office for administrative purposes just before 11am," said deputy commissioner James Smalberger on Monday.
"She is standing outside … her parole condition applies with immediate effect."
The correctional supervision and parole board approved that she be released on parole from August 19.
She had been placed in a "maximum category" that stipulated strict parole conditions.
Visser was serving a seven-year jail term on 11 charges, which included two of indecently assaulting an 11-year-old girl and a 14-year-old girl, and soliciting a 13-year-old girl to commit indecent acts.
She was also sentenced on a charge of defrauding a children's home to get them to allow children to spend weekends with her and her then lover Dirk Prinsloo.
Visser was convicted in 2009 and began serving prison time – after a failed application to appeal her sentence – in 2010.
She was previously turned down twice for release on correctional supervision by the parole board.
Visser was nicknamed "advocate Barbie" by the media because of her previous image of dyed blonde hair and surgically enhanced breasts.
The ANC Women's League said it respected the decision to grant parole to Visser.
"Ms Visser has served half of her seven-year jail term as required by law and met the necessary prescripts to be granted parole," said league deputy president Nosipho Dorothy Ntwanambi.
"The women's league continues to believe that the South African criminal justice [system] actively seeks to rehabilitate offenders and once conditions for such have been created then reintegrate them back to society."
She said the women's league was disappointed that Prinsloo had still not been prosecuted and convicted for his role in violating and abusing young children.
"Dirk Prinsloo must be tried for his crimes and he must be made to feel the full wrath of the law of this country which values and protects its children."
Prinsloo fled South Africa to avoid the trial but was later convicted of bank robbery in Belarus and is serving a 13-year prison sentence after which he will be extradited. – Sapa