A 34-year-old who groomed and performed sexual acts on a young boy three times within a nine-month span has been jailed for four years and three months.

Sean Paul Clemenger appeared in the Dunedin District Court on Monday, having pleaded guilty to three charges of performing an indecent act on a seven-year-old boy between July 2006 and April 2007.

The court heard that Clemenger and the victim were family friends, and that the offending took place in the homes of the victim and Clemenger, as well as in the flax bushes of a church playground.

In an emotional statement, the mother of the victim said her son had ongoing trust issues, and that the relationship between he and the son had broken down as a result of the incidents.

As well as the three separate incidents, Clemenger was also being sentenced for possessing over 140 explicit videos and 20 images, as well as distributing 38 films and three slide shows, between January and April this year.

The court heard that Clemenger shared 16 explicit movies and three slide shows on a public network site, that allowed people to access his private folder, between January 14 and 18 this year. 

Then in April, he sent a further 21 explicit movies and images on the same public network site.

Police then executed a search warrant, and 146 videos and 20 images were found on Clemenger's computer featuring girls as young as four, and boys as young as eight. 

Crown prosecutor Craig Powell told the court he had only made the confession to abusing the boy once a complaint had been made.

Defense counsel Andrew Dawson said Clemenger expressed genuine remorse, and that he had hated himself for what he had done to the victim.

Judge Michael Turner said the offending was grave, and a serious breach of the boy’s trust. 

"You destroyed long-standing family relationships, and between the victim and his family," Judge Turner said.

"The offending occurred when he should have been enjoying the innocence of childhood."

Clemenger was convicted and sentenced to a concurrent prison sentence of four years and three months.

He was also ordered to be included on the sexual offenders register.