Rhys Bennett Nelson, 22, has been charged with grooming a child between the ages of 14 and 16 for unlawful sexual activity and three counts of possessing child abuse material.

Nelson pleaded guilty to the offences earlier this year and was due to be sentenced on Wednesday.

However, the case was adjourned due to a mix up of dates from legal counsel. Nelson will now learn his fate next month.

During September last year, a 15-year-old girl received a request on Snapchat from Nelson, to which she accepted due to having several mutual friends on the app.

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He began sending pictures to the girl, asking her to go for a drive, and persisted with messaging her after she informed him of her age.

The girl ignored messages from Nelson, including ones that said 'I want you' and 'I already said I'm too old for you but I want your body', according to agreed facts tendered to the court.

After she received a video of him masturbating, the girl felt "disgusted" and reported what she saw to her mother, who then reported to police.

The girl was able to identify Nelson due to pictures he sent that partially revealed his face and tattoos on his arm.

Police raided Nelson's home in November and seized a hard drive, laptop, and two mobile phones which were stored in his cupboard.

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After a forensic examination, 117 videos and three images depicting horrific child porn were unveiled from the devices.

Some of the videos contained female children as young as six-years-old being forced to perform sexual acts on others.

A further 1393 child abuse images were found on his iPhone.

After his arrest, police interviewed Nelson who initially said his Snapchat account was hacked more than once and that he was "pretty sure" people in the videos on his devices were over 16.

However, when shown the videos, he agreed children were depicted, but denied having a sexual interest in child pornography.

He also admitted to sending the video of himself masturbating.

Nelson will return to Wollongong Local Court on September 7.

Read more Illawarra court and crime stories here.