The woman arrived at the airport last month when an ion scanner detected a high level of narcotics in her suitcase, which reportedly contained e-liquid for an electronic cigarette, The Korea Herald reported, citing a source from Daegu Regional Customs on Nov. 18.
She explained that the detected item was liquid for personal use in her e-cigarette. In response, customs officers deployed a different device to conduct a more thorough search.
The scan identified an object near her pants, which turned out to be a sanitary pad.
A female customs officer escorted the woman to a separate room, where the sanitary pad was inspected for 20 minutes. After finding no traces of narcotics, the tourist was allowed to leave, Yonhap News Agency reported.
The incident has sparked widespread criticism on social media.
Customs officials, however, defended the invasive search, stating it was lawful and an "unavoidable measure" due to the recent rise in cases of drug smuggling through body concealment, the South China Morning Post reported.
Officials emphasized that all procedures are conducted in compliance with legal protocols and that they make every effort to minimize inconvenience for travelers during inspections.
"We seek cooperation and understanding regarding any inconvenience that may arise as part of thorough customs inspections to prevent drug smuggling," officials added.