A Polish man has been charged with trying to import about four kilograms of cocaine into Australia hidden in the lining of his suitcase.

Customs and Border Protection officers questioned the 39-year-old man when he arrived at Sydney Airport on a flight from California on Wednesday.

The officers became suspicious that the man was concealing something and an X-ray of his suitcase revealed four packages in the lining.

Initial tests indicated the presence of cocaine, Customs and Border Protection said in a statement.

Australian Federal Police said it was worth about $1 million in street value.

The man has been charged with importing a marketable quantity of a border controlled drug and is due to appear in Sydney's Central Local Court on Thursday.

Further tests will be carried out to confirm the exact weight and purity of the substance.

The offence carries a maximum penalty of 25 years jail and/or a $550,000 fine.