Police began their investigations earlier this year after being told of allegation a Nowra man had been sexually and indecently assaulting a teenage boy.

Detectives from the Shoalhaven Local Area Command on Friday arrested a 29-year-old man at Nowra Police Station.

The man was subsequently charged with 24 counts of aggravated sexual assault of a child and two counts of aggravated indecent assault.

He is due to appear before before Nowra Local Court on Saturday.