South African Revenue Service (SARS) officials have arrested a South African student who allegedly had US dollars to the value of almost R10m in her hand luggage when she boarded a flight at OR Tambo International Airport.

The student was apparently en route to Hong Kong.

According to SARS spokesperson Sicelo Mkosi, the money was counted and amounted to $630 700.

Mkosi said the flight was scheduled to leave when the officers pounced.

"Initially, she denied having currency in her possession, but after further questioning, she admitted that she had a substantial amount of money in her backpack," Mkosi said in a statement.

He said she was taken to the customs search area where she was placed in an interview room and asked to complete a traveller card.

"The passenger verbally stated that she had 650 000 United States dollars in her bag. She admitted that she was not the owner of the currency, nor could she supply any proof of ownership," Mkosi added.

A criminal case of smuggling currency and failure to declare it has been registered, he said.

"SARS remains appreciative of the constructive collaboration between ACSA (the Airports Company of SA), SAPS (SA Police Service), DPCI (Directorate for Priority Crime Investigation), Asset Forfeiture Unit (NPA) and the State Security Agency (SSA), which is yielding positive results in the fight against the scourge of illicit financial flows," Beyers Theron, Acting Chief Officer: Customs and Excise, said.

Police could not be immediately reached for an update on the case. - New