The southern end of Belmore Basin will remain closed this week as officials hunt for the "elusive" sewage leak that was discovered last month.
The leak was noticed by Illawarra resident Adam Nurzynski on January 11 when he was walking near the harbour.
Noticing a foul smell, he traced it to a milky white water coming from the cracks in a sandstone wall near the jetty. Sydney Water was called in and began searching for the origin of the leak, including digging up the car park near Belmore Basin.
On January 17 Wollongong City Council closed the beach and warned people not to swim in the water.
This weekend, the southern end of the basin remained closed as a small amount of sewage continued to seep from the seawall.
"Crown Lands are conducting ongoing investigations in consultation with Sydney Water, EPA, NSW Health and Wollongong City Council," a spokeswoman from the Environment Protection Authority said.
"There is risk the seep may continue for a period of time as investigations continue and the exact source of the seep continues to be elusive."
The spokeswoman said the authority has been undertaking regular water quality tests at Belmore Basin and will make the results publicly available on Thursday.