A 29-year-old tourist from the Philippines has spent five days in custody after Australian Customs officials mistook iced tea for drugs.

Tourist, Maria Silva bought three 800 gram bags of Nestle iced tea on her way to the airport in Manila before her flight to Melbourne.

On arrival at Melbourne Airport she was detected by sniffer dogs and arrested by Customs.

Customs' initial tests showed the packets contained 2.44 kilograms of methamphetamines.

Customs later revised its results to amphetamines and Ms Silva was charged with importing a commercial quantity of drugs into Australia.

It was only after she spent five days in custody, unable to contact family or friends, that further tests by a Federal Police forensic team revealed the supposed drugs were in fact powdered lemon-flavoured iced tea.

The Melbourne Magistrates Court heard the powdered formula contains an ingredient that is often mistaken for drugs.

The Magistrate awarded Ms Silva $5,000 in costs for what he described as "an unfortunate set of circumstances."

Ms Silva burst into tears as she was released from custody today.

Outside court, her lawyer, Michael Pena-Rees said Ms Silva had bought the iced tea, which is cheaper in the Philippines, for her friend as a treat.

Mr Pena-Rees says Customs is yet to apologise for its mistake.