Investigators in southwest China's city of Kunming have found that a local official who was recently implicated in a group sex scandal was a victim of extortion. Two suspects have been detained, local police said.

Police also ordered the detainment of the official, as well as two others, for 15 days for committing illegal sexual acts and videotaping the proceedings.

Another two, who were allegedly extorted money from the official, were detained on criminal charge.

The official, an employee of the city's development and reform commission surnamed Cheng, was targeted by an extortion ring on a social networking website, police said, adding that the official was "lured" to join a group sex gathering held in April in an apartment equipped with hidden cameras. The ring then extorted money from the official by threatening to post footage from the gathering on the Internet.

Still images from the footage managed to find their way online, prompting public outcry over the official's actions.

Previous reports said Cheng went to the local police the same day that the images were leaked and claimed that he had been blackmailed for 63,000 yuan (10,000 U.S. dollars).

Cheng was expelled from the Communist Party of China (CPC), as the Party's municipal disciplinary committee described his actions has having "severely damaged social morality."

Although Cheng was a victim of extortion, immoral behavior by Chinese officials has drawn a great deal of public criticism.

The party's disciplinary authorities have repeatedly called for harsher punishments for officials who commit adultery, abuse their power to obtain sexual favors or purchase the services of prostitutes.

Cheng's case was revealed shortly after another official in central China's Henan Province was punished for his role in a recent sex scandal.

Tian Hanwen, a legislator from the province's Ruyang County, became notorious overnight after photos of him having sex were posted online by an anonymous woman, who has accused Tian of using his official power to take advantage of her.