Police said Monday they are tracking down two individuals based in China for allegedly masterminding an extortion scam that involved handing over beverages laced with drugs to random high school students in Seoul.

The two -- a South Korean national in his 20s surnamed Lee and a Chinese national in his 30s surnamed Park -- are accused of ordering a South Korean national surnamed Gil to make and supply methamphetamine-laced beverages, the Seoul Metropolitan Police Agency said.

Four other individuals then handed out the beverages to the students in Gangnam Ward, southern Seoul, on April 3 after tricking them into believing they were helpful for concentration, according to the SMPA.

The SMPA alleges that the two suspects have connections to crime rings based in China that specialize in voice phishing scams, with the possibility of a higher-ranked mastermind behind all the schemes.

The SMPA said it has sought arrest warrants for the two and has made a request for cooperation from Chinese authorities.

At least seven students reported exhibiting abnormal symptoms after drinking the beverages given to them by a group of people in two separate areas in Gangnam that are lined with private tutoring academies. Another parent later reported drinking the beverage.

An investigation later revealed that the bottles contained methamphetamine, and false labels were attached claiming that they were intended to improve memory and concentration.

Gil, who was detained Friday, is accused of sending drug-laced beverages through express buses and delivery services to the four individuals. Another detained suspect, surnamed Kim, is accused of disguising incoming calls from China as local mobile phone numbers to blackmail the parents of students.

Police have sought arrest warrants for the two, and a Seoul court is set to hold hearings later Monday.

The four individuals, who allegedly offered the beverages to students, claimed that they were not aware that the beverages were laced with drugs and distributed them only as part-time workers hired through the internet. (Yonhap)