Police were called to Wollongong Harbour about 3pm Tuesday, after members of the public allegedly noticed saw the man photographing girls as they were swimming.

Officers from Wollongong Police District attended and spoke with a 52-year-old man, who had by then been apprehended by members of the public.

The alleged incident occurred near a mobile police command centre set up for Australia Day, and the area was soon swarming with uniformed and plain-clothes officers.

The man's phone was seized for forensic examination.

Following inquiries, the man was arrested and taken to Wollongong Police Station.

His Coniston home was searched a short time later and items of interest seized for forensic examination.

The man was charged with nine counts of possess/produce child abuse material.

Police will allege in court that the man's phone contained images of girls - aged between 11 and 14 - taken in the Wollongong and Towradgi areas between December 2020 and January 2021.

He was refused bail to appear in Wollongong Local Court later today.