A routine search of a man's check-in luggage at OR Tambo International Airport led to the discovery of what is believed to be cocaine worth R1.5m, according to police.

The 23-year-old man had arrived in South Africa from Sao Paolo in Brazil when members of the multi-disciplinary narcotics team searched his bag.

"The officials discovered drugs, suspected to be cocaine, in his luggage. The suspected cocaine, with an estimated street value of R1 522 500, was confiscated," police spokesperson Lieutenant Colonel Katlego Mogale said in a statement.

The man is expected to appear in the Kempton Park Magistrate's Court on Thursday for possession of and dealing in drugs.

In an unrelated drug bust, a  24-year-old man was arrested last week at the same airport for allegedly attempting to smuggle suspected drugs onto a flight to Frankfurt in Germany.

Mogale said that 45kg of suspected Khat, which had an estimated street value of around R900 000, was found.

"The suspect was arrested by the alert members of the narcotics team after searching his check-in luggage."

The man appeared in the Kempton Park Magistrate's Court last Friday, where bail was denied.

His case was postponed to July 30 for further investigation.