"We are legally obliged to comply with privacy legislation and the Health Information Privacy Code, which prevents us from providing personal information relating to a prisoner's healthcare," said a spokesperson.
They did explain how someone like Mikus would be treated behind bars with a terminal illness.
"Corrections has a statutory obligation to ensure prisoners receive the same standard of care that they would receive in the community.
"All prisons provide primary healthcare services, which include general practitioner services, nursing, basic dentistry and some disability support services.
"Prison health centres do not provide hospital-level care or specialist services."
Teresa's family have been contacted for comment.
Mikus got away with murder for 15 years - but when advances in DNA enabled police to match him to samples taken at the time of Teresa's brutal killing, he was finally captured.
He had been a suspect early in the investigation but had an alibi that was not challenged.
Mikus has been denied parole several times - most recently in April 2016.
At that hearing the Parole Board made a postponement order for five years meaning they would not see Mikus again until December 2020.
At the time board panel convenor Justice Marion Frater said Mikus had consistently failed to engage with the parole process "from the beginning".
"Nor has he taken any steps to address his very serious sexual and violent offending. He has declined to participate in assessments for the Parole Board and declined to participate in any interventions with a departmental psychologist," she said.
"Given his assessed very high risk of sexual reoffending we are satisfied that even if Mr Mikus changes his mind and engages now, it will take at least five years before there is any prospect that he could safely be released.
"Accordingly, we make a postponement order of the maximum duration."
A spokesman for the Parole Board said his postponement order had not changed and no application had been made for an earlier hearing date or compassionate release.
After he was sentenced the Herald revealed Mikus had a raft of offences to his name, starting in his teens.
He was sent to prison for the first time in 1977 after he indecently assaulted a girl under 16.
Mikus also has convictions for multiple burglaries, assault with intent to rape, fraud, bigamy, escaping custody and various other driving, drug and weapons offending.