THE seizure of $30 million from criminals in 12 months may be only a drop in an ocean of black money, the state's crime watchdog says.

The NSW Crime Commission, in its annual report tabled in State Parliament last week, says ports are infiltrated by organised crime, and Australia is a particular target for drug rings because of high profit margins. Referring to the "porosity" of ports, the report says criminal involvement at seaports and airports is a concern.

"In particular, persons working in baggage and freight handling, stevedoring, transportation and related industries are known to include criminals and persons with criminal connections."

The commission says its haul of assets and cash, $12 million more than in the previous year, would have little effect on the black economy. "While $30 million seems a large sum to take out of the hands of criminals in a year, the scale of money laundering and accumulation of proceeds of crime is such that the amount confiscated can only have a slight effect."

The supply of cocaine may also be rising, with a big drop in the price per kilogram over the year a good indicator of increased availability.

The profit margins for importers made cocaine an attractive option. The price per kilogram in Australia is often 10 times that of the purchase price overseas, the report says.

The commission had authorised 31 "controlled operations", or undercover operations, in the past 12 months.

It has been criticised over a controlled operation dubbed Mocha in 2004 in which it authorised the release of six kilograms of cocaine onto Sydney's streets.

The Government was forced to investigate when the operation became public knowledge.

In September the High Court made a unanimous finding that the sale would have been likely to endanger seriously the health or safety of some drug users.

The commission, renowned for its ability to compel alleged criminals to answer questions in its so-called star chamber and to seize cash and assets, has made several prominent busts recently.