Responding to inquiries why only virgin students were wanted in a medical study, a member of the research team at the Tumor Hospital of Peking University said that it was in line with internationally accepted norms, according to the Beijing News.

An online post on Wednesday by the hospital sought to recruit 100 virgin students, aged between 18 and 24, for medical research. Each of the students will provide 3 to 5 milliliters of venous blood as part of a program to study the human papillomavirus. Each donor will receive 150 yuan ($24).

Some netizens were puzzled why only virgins seemed suitable.

A researcher, surnamed Liu, replied that the team needs virgins because of the low incidence rate among this group of the human papillomavirus, she told the Beijing News.

"The team has collected more than 50 samples," she said.

The post was deleted on Thursday evening, Beijing News said.