A cult leader who used his influence to rape several minors has not changed his behaviour and should not be granted parole, the NSW State Parole Authority says.

William Kamm, a 62-year-old self-proclaimed prophet who claims to receive divine instruction from the Virgin Mary, was jailed in 2005 for at least three-and-a-half years for raping and assaulting a teenager in 1993.

In 2007, a seven-and-a-half-year non-parole period with a maximum of 10 years was added to his sentence for other sex offences.

The cult leader was convicted of five counts of sexual intercourse with a minor by a person in authority, four counts of aggravated indecent assault against a minor and one count of aggravated indecent assault.

Kamm, known to followers as "Little Pebble", is able to apply for parole on April 13, but the parole authority believes he should serve his full sentence.

"He hasn't yet completed any programs that address his offending behaviour," a spokesman told AAP on Friday.

A statement from the State Parole Authority (SPA) said it intended to refuse parole.

"Given that Mr Kamm remains an untreated sex offender, his release to parole is not recommended," the statement said.

Kamm has previously said he was a messiah, and would usher in a new holy era by choosing 12 queens and 72 princesses to conceive an "immaculate race".