KOTA KINABALU (THE STAR/ASIA NEWS NETWORK) - Malaysian immigration officers responding to a call to rescue three women from a prostitution ring made a surprising discovery on their raid - over RM13 million (S$4.2 million) in cash.

Sources told The Star that the department received a tip-off that three Filipino women were being held at a hotel in downtown Kota Kinabalu, Sabah by a prostitution syndicate.

When officers raided the hotel early Friday (Nov 24), they found the three women in the hotel spa and another 17 Filipino women in other rooms.

They also discovered piles of cash - RM11.9 million in a room in the hotel and another RM1.17 million at an apartment next door.

"Some of the cash were stuffed in envelopes and plastic bags while some were just left in the open since there were so much of it," said Immigration director-general Mustafar Ali.

Three men - believed to be middlemen for the syndicate - were arrested.

Datuk Seri Mustafar said two of the men were Malaysians and the other was a Filipino, and they were aged between 30 and 50 years old.

Mr Mustafar said the department would investigate to determine the source of the money and what it was going to be used for.

He said the case was being investigated under the Anti-Trafficking in Persons and Anti Smuggling Act.