(CFP)

Ma Yaohai, an associate professor at Nanjing University of Technology, has been sentenced on May 20 to three-and-a-half years imprisonment for organizing group sex parties.

The Qinhuai District People's Court in Nanjing, Jiangsu Province, convicted Ma and 21 other people on charges of group licentiousness and sentenced 19 of them to various jail terms. They are the first people in 20 years to be given criminal penalties for the crime.

"Ringleaders and persons who repeatedly take part in licentious activities shall be sentenced to fixed terms of imprisonment of no more than five years, criminal detention or public surveillance," says Article 301 of China's Criminal Law.

The court found the 14 men and eight women guilty of engaging in dozens of group sexual activities from 2007 to 2009 after making contact via the Internet.

Ma, 53, admitted the facts, but argued that, as all the defendants were voluntary adult participants, they were not guilty of any criminal activities.