Image: NSW Police

Almost 2.5 million hits of the drug ice are off our streets following a joint state and federal police operation.

Tens of thousands of highlighter pens were found to contain the pre-cursor ephedrine after arriving in Sydney from China earlier this month.

The seized drugs have an estimated street value of $120 million.

A 27-year-old man has been charged, while two others were arrested then released pending further enquiries.

The maximum penalty for this offence is 25 years imprisonment and/or a fine of $900,000.

ABF Investigations Superintendent Garry Low says over two tonnes of ephedrine has been seized at the NSW border alone over the past 12 months.