By Lee Han-soo

A Thai woman's wits have led to her rescue and that of four others from a brothel in South Korea.

The Busan Metropolitan Police Agency revealed the case on Wednesday.

The incident started when the five women visited a Busan supermarket on May 16 under the "guidance" of a Korean man.

The women were regular customers who visited late at night to buy daily necessities.

On May 16, the women bought products while the Korean man stood just outside the supermarket. But something unusual happened when they paid the bill.

As one of the women extended her cash-filled hand to the casher, he realized there was more there than he expected -- a hand-written SOS message hidden inside the cash.

"Help the police. I was caught in the fourth floor of the building," read the note in English, Korean and Thai.





The note the woman handed to the supermarket clerk. / Yonhap



It also said in poor Korean that she had been deceived and needed his help to call the police. The clerk realized the urgent nature of the issue and penned an answer: "112 call, helping you." 112 is Korea's police hotline number.

But the woman stopped him and left with the others.

When his shift finished, the clerk handed the note to police with a phone number given to save store points.

Police checked the number and traced it to a person who they had previously caught operating a brothel.

But during the initial investigation, police failed to find the "fourth floor of the building" where the women were being held captive.

They did discover a suspicious fortune-telling shop but did not investigate further as it seemed closed.

The women were finally rescued on May 18 after the woman specified the fortune-telling shop as the location through social media.

A foreigner support center in Osan picked up the SNS post and reported it to the Gyeonggi Nambu Provincial Police Agency, which told the Busan Metropolitan Police Agency.

"I believed that she was afraid that if I immediately reported the case to the police she would face dire consequences by the Korean man waiting outside," the supermarket clerk said.

"I was too afraid to escape on my own," the Thai woman, who handed the note to the clerk, told police. "I wrote the note with the little Korean I learned from customers."

The ringleader, surnamed Lee, had held five Thai nationals and forced them into prostitution for 90,000 won ($70) to 160,000 won a customer.

Lee and the broker who brought the women to Korea lured them with the prospect of getting jobs at legitimate Thai massage parlors.

But when they arrived, Lee took their passports and locked them inside the building, forcing them to have sexual intercourse with customers.

Lee said he advertised his illegal business on the internet and met customers at subway stations to avoid detection. He said he asked for an official identification card or a salary check slip to see if the customer was an undercover police officer.