Some 25 kilograms of heroin with an estimated street value of $4.5 million were seized by Customs and Border Protection officers.

Customs and Border Protection officers at the Sydney Container Examination Facility examined a shipping container declared as kitchen and hardware items.

Customs and Border Protection officers found 26 cardboard boxes containing a large number of bolts. Upon further inspection, officers found a white substance concealed within the bolts.

Initial testing of the substance indicated the presence of heroin.

Further forensic testing will be undertaken to confirm the exact weight and purity of the substance.

The matter has been referred to the Australian Federal Police for further investigation.

The maximum penalty for importing a commercial quantity of heroin is life imprisonment and/or an $825,000 fine.