A Melbourne man charged with trafficking about $2 million worth of drugs has been remanded in custody.

Troung Nguyen, of Derrimut, was arrested at Southern Cross Station after getting off a bus from Sydney early Wednesday morning.

Police say the 34-year-old had swallowed heroin and was carrying two kilograms of methylamphetamine - also known as ice - in a black suitcase.

Prosecutors estimate the drugs' wholesale value at $400,000 and a street value of $2 million.

They say Nguyen described himself to police as a drugs courier but refused to say who he was working for.

His lawyer told the court Nguyen is a drug addict who will use his time in custody to get clean.

He will return to court in December.