Security cameras in Crown St Mall proved their worth yesterday when two youths were arrested by police in the middle of a launch to expand the CBD surveillance system.

Security guards monitoring the cameras located one 17-year-old having a coffee in the mall who was wanted for an outstanding arrest warrant for dishonesty charges.

The second youth was in breach of bail and was in the mall with an adult.

Both were arrested by police who were on standby for the expansion of the closed-circuit television system throughout the CBD.

Forty cameras were activated in the wider city centre yesterday, complementing the first 40 that were installed in Crown St Mall in January 2007.

The cameras extend from Piccadilly Centre in the west, WIN Entertainment Centre in the east, north to known trouble spots in Market St and south to Burelli St. Included in the new surveillance are the city's six main hotels - Dicey Riley's, Cooney's Tavern, Illawarra Hotel, Glasshouse Tavern, Oxford Tavern and Harp Hotel.

Wollongong City Council general manager David Farmer said the cameras could record activity 24 hours a day, with footage monitored through a centralised control room that could be logged into by Wollongong police.

The system alerts police to crimes in progress while also providing security footage after the crime has occurred.

The cameras have been installed as part of the City Centre CCTV Street Camera Program, a joint Wollongong council and Wollongong City Centre Ltd initiative that was awarded a $485,000 Federal Government grant under the National Community Crime Prevention Program.

Mr Farmer said the CCTV network, which would assist with the reduction of antisocial behaviour and criminal activity, was the first full internet protocol CCTV street system in Australia.

"These latest CCTV cameras will help the community, shoppers and businesses feel more secure, which is vital as we continue to make our city centre safe, clean and attractive to the community," Mr Farmer said.

Wollongong City Centre general manager Paul Fanning, who initiated the program, said since its launch, almost 900 arrests had been made for offences ranging from petty crimes, to credit card fraud, shoplifting, assault and drug dealing.

"It is an amazing effort from our special constables who work closely with the NSW Police," Mr Fanning said.

Wollongong local area commander Superintendent Wayne Dedden said the system provided an advantage for police.

"It produces high-quality images and footage," he said. "We now have PTZ (pan tilt zoom) camera coverage in front of the busiest pubs in the city centre along with major public spaces."

He disputed past research that suggested CCTV cameras displaced crime to other areas.

"The system is helping us catch a lot more offenders," he said.

Mr Fanning said details on the location of some new cameras was being withheld for security reasons.