The man who raped and murdered six-year-old Teresa Cormack has been denied parole because his risk of further sexual offending is too high.

Jules Mikus was sentenced to life in prison and preventive detention in 2002 after he was found guilty of the 1987 murder of the schoolgirl.

Teresa's murder went unsolved for 15 years, until DNA advances led to the arrest of Mikus - who had been a suspect early in the investigation but had an alibi that was not challenged.

Mikus appeared before the Parole Board in December and was denied an early release.

On April 1st, the board met again and decided to postpone his next appearance for three years.

Parole Board member Justice Marion Frater says Mikus has consistently failed to engage with the parole process.