The 40-year-old was arrested in Goulburn on Wednesday and charged with 30 offences allegedly committed against 13 girls aged between 12 and 17 who lived at various locations across NSW and the ACT.

He was charged with four counts of sexual assault, two counts of aggravated indecent assault, two of committing an act of indecency, one of using a carriage service to procure a person under 16 for sexual activity, seven of using a carriage service to groom a person under 16 for sexual activity, and 14 of disseminating child pornography.

The man was arrested following an eight-month investigation by the Child Protection and Sex Crimes Squad.

Since July last year detectives attached to Strike Force Elim have been investigating alleged sexual-related offences against the 13 females, leading to charges against the man who has been refused bail, and remanded in custody to face Parramatta Local Court on April 3.

Police alleged the girls were initially contacted via Internet chat rooms and then mobile phone, before the Nowra man arranged face-to-face meetings with some of the girls.

In some cases the teenagers were allegedly sexually assaulted, according to police.