Obviously we believe we have some very, very significant players and we would like to think that this is going to have a very significant effect

Police Commander Rod Lambert

Eight people were arrested as officers raided houses and properties across the city on Friday, the climax of a 10-month long investigation, Operation Kayak.

More than 30 people have now been arrested during the operation, and police say they are confident that they have netted Australia's major ecstasy traders.

Police Commander Rod Lambert told reporters: "Obviously we believe we have some very, very significant players and we would like to think that this is going to have a very significant effect."

Mr Lambert said an amount of what he described as commercial quantities of amphetamines, cocaine and ecstasy was also seized.

Drug warning

The seizure far exceeds Australia's previous record haul of ecstasy-related drugs.

• In April, about half-a-million ecstasy tablets were discovered hidden inside a shipment of pineapples aboard a Chinese cargo ship.

• In December 2000, police in Sydney seized 105kg of ecstasy.

• Last month, police dug up one tonne of cocaine buried on a remote beach in Western Australia's

On its own, ephedrine is a legal stimulant often used to provide short-term energy boosts to enhance athletic performance, helping people exercise longer and feel more alert.

It is found in some cold and hayfever remedies and dietary supplements.

Ephedrine is on the list of substances banned by international athletic federations.

It has been linked with increased likelihood of heart attack, paranoia, depression and stroke.

The BBC's Red Harrison says police are warning that there could now be a drought of cocaine, hashish, ecstasy and amphetamines in Melbourne, and are urging drug users to be extremely wary of what might be offered on the streets to replace the confiscated drugs.