An associate professor of a university in China, who founded an online wife-swapping club, has been charged for prurient interest (morbid and degrading interest in sex).

The 53-year-old professor, surnamed Wang, was said to have participated in 18 of the 35 gatherings organised by the club.

He was also the oldest and highest-educated member of the club, Xinhua Agency reported.

Wang is facing up to five years' jail along with 21 men and women, who were arrested by police following a complaint over the wife-swapping activities in August last year.

Recently, they were charged at the Qinhuai District Court in Nanjing for organising sexual activities between May 2007 and August 2009.

Wang, an Alzheimer's patient, was introduced to the wife-exchanging activity by a net pal. Soon, he left the group and set up his own circle.

He managed to draw a large group of followers and at its peak, the club had over 190 followers.

Wang, who had two failed marriages, had been living with his mother at the hostel of his university in Nanjing.

Prior to Wang's arrest, he had disbanded the group after he was rejected by young women a few times, according to Ming Bao.

Most of the events were conducted at his home.

Although Wang had no partner to swap with, he used to sweet-talk other participants to exchange with him.

When no one agreed, he would observe them quietly by the side.