The mystery of hundreds of kilograms of cocaine washing up on NSW beaches continues to confound police as more of the prohibited drug is found along the coastline.
About 256kg of cocaine in blocks has been recovered at locations spanning from the south coast to Newcastle since the days before Christmas.
Detectives are working with specialist resources including PolAir and Marine Area Command, as well as Australian Border Force and Surf Life Saving NSW, to seize any outstanding packages and determine their origin.
The latest discovery - a 1kg block of cocaine - was found ashore at Nambucca Heads on the mid-north coast on Monday.
In less than one week in late December, 124 barnacle-covered 1kg "bricks" of suspected cocaine were retrieved from the surf between Sydney and Newcastle.
NSW Police were initially called to Magenta Beach, on the Central Coast, on December 22 after a member of the public found a suspicious package containing 39 sealed packets.
On Christmas Eve, seven more individually wrapped bricks washed up on Magenta, Pelican, Blacksmith and Avoca beaches, Pentaloon Bay and North Steyne Beach.
On the morning of Boxing Day, water police were called to the Barrenjoey headland, Sydney's most northern point, where a fisherman found a blue barrel stuffed with another 39 packets of cocaine.
The cocaine blocks carry various labels such as "Tesla", "Zoe" and "R-Z".
Detective Superintendent Peter Faux said police believed the cocaine had been in the ocean for some weeks before washing ashore.
"Our detectives have analysed tides as well as barnacle growth on the packages to determine the blocks were only in the water a short amount of time before washing ashore - no more than six weeks," he said on Thursday.
Det Supt Faux urged the public to help by providing information and continuing to report the discovery of packages.
"Beach-goers are reminded that being in possession of a prohibited drug is a criminal offence," he said.