A tip-off from Chinese authorities has led to more than a tonne of the drug precursor chemical ephedrine being seized, which could have been used to produce almost $700 million worth of ice.

A joint investigation by the Australian Federal Police and Australian Border Force has resulted in four people being arrested over the drug bust.

Some of the 1300 kilograms of seized ephedrine is seen during an Australian Federal Police press conference in Melbourne on Wednesday, Credit:AAP

The AFP said the arrests came after China’s National Narcotics Control Commission alerted Australian authorities about an organised crime syndicate.

Australian Federal Police estimate the seized ephedrine had the potential to make 922 kilograms of ice, with a street value of about $691.5 million.