Mark Russell Stenning (51), of Dunedin, was on a five-year extended supervision order (ESO) - a backstop used by Corrections to monitor dangerous offenders once they have finished serving prison terms - which ended in March 2017.
However, he soon abused his new-found freedom.
Police executed a search warrant at Stenning's home on an unrelated matter in October 2017.
They seized a cellphone, Xbox games console, tablet and USB drives, which were sent for forensic electronic examination.
On one of the portable drives, police found four images.
They had been deleted, the Dunedin District Court heard yesterday, but were still visible to investigators.
One of the files featured a child under the age of 8 involved in penetrative sexual activity, while the other three showed girls under 10 naked.
When spoken to by police some months later, Stenning said he only put TV shows and movies on the USB drive and did not know where the objectionable files came from.
He later pleaded guilty to two charges of possessing objectionable material.
Stenning has more than 20 convictions for sexual offences, including doing indecent acts on and in front of young girls.
He was jailed for nearly three years in 2010 for using another person's computer to download explicit images of young children and when he was released, he breached the ESO.
Conditions of the order barred him from entering or loitering anywhere children might congregate but in 2015 his GPS tracker showed he had been to Wanaka's Puzzling World - an attraction popular with families.
Stenning also breached it by possessing an internet-capable device around the same time.
He was jailed for four months for the indiscretions but appeared in court again in 2017 for visiting the Oamaru Blue Penguin Colony.
Stenning was sentenced to community work.
Defence counsel John Westgate told the court yesterday his client had made significant strides in changing his life and now had stable accommodation and supportive friends.
However, Judge Kevin Phillips said there was no option but to incarcerate the defendant.
Legislation states there is a presumption of imprisonment if there is repeat offending under the Films, Videos and Publications Classification Act.
There was nothing in Stenning's circumstances to displace that, the judge said.
He jailed the defendant for nine months - to the objection of the man's friends.
''He's going to lose his home now and that's not fair - everything he's worked so hard for,'' one woman said as she left court.
