Clean-up efforts along the NSW coastline have increased after 10 more containers were confirmed to have fallen from the APL England last weekend in rough seas.
NSW Maritime on Friday said 50 shipping containers - not 40 as initially thought - went overboard south of Sydney on Sunday when the Singapore-flagged ship was en route to Melbourne.
Fifteen of the containers have been accounted for so far.
A preliminary inspection of the troubled cargo ship - which is now detained at the Port of Brisbane - has uncovered a major defect and serious concerns with how the load was secured, authorities say.
NSW Maritime acting executive director Alex Barrell said there are about 100 people working between Wollongong and Port Stephens to remove containers and their contents from beaches and bays.
"From an audit carried out in the Port of Brisbane, the number of lost containers has been revised to 50 up from the original 40 reported missing, so we have an even bigger job ahead of us," Mr Barrell said in a statement on Friday.
"Twenty-four of these containers were being transported empty and 26 contain a variety of goods."
Mr Barrell said 80 per cent of workers are cleaning up debris washed ashore with efforts on Friday focused on Cronulla and nearby Sydney beaches at Little Bay, Maroubra and Tamarama, as well as at Newcastle and Port Stephens.
Three tug boats were deployed on Thursday to secure containers and tow them to Broken Bay on the NSW Central Coast for safe disposal.
Five containers which washed onto Birdie Beach have now been brought ashore for disposal.
Four containers offshore near Norah Head on the Central Coast are in the final stages of being removed from the water overnight.
One container was lost during the tow with efforts under way to relocate it.
A tug boat deployed from Newcastle on Thursday is still retrieving five containers which washed ashore south of Bateau Bay after they broke up on nearby rocks and spilled their contents.
A Botany-based tug boat salvaging one container off Port Kembla is due to arrive in Broken Bay later on Friday.
Australian Associated Press