A judge's sentencing decision in a child sexual abuse case has been described as "offender-friendly" by a conservative justice lobby group.

A Wellington man was sentenced to six years and nine months in jail on Friday for forcing his nine year-old niece to watch pornography while he touched her and masturbated. The offending took place over a five-year period.

Scott Guthrie, Spokesperson for Child Abuse at the Sensible Sentencing Trust, said that without a minimum non-parole period, the man is eligible for parole in a third of his sentence.

"The judge could've put a minimum non-parole period which would've given him time to be rehabilitated in prison," Guthrie said.

"Here we've got a sexual predator who's going to be released from prison in twenty-seven months and he'll do what he knows."

Guthrie described the judge's decision as "wrong" and "offender-friendly" for "not taking the victim into consideration."

Fairfax Media reported that there were no victim impact statements submitted for the sentencing hearing as the mother of the victim supported the offender.