Ten mid-ranking officials in Southwest China's Chongqing municipality have been removed from their posts, as authorities continued to investigate an online sex-video scandal that led to the sacking of a district official last year.

The officials included four district-or county-level Party chiefs and the head of a Party discipline inspection committee at the municipality's transportation committee, the municipal government said on its micro blog on Thursday night.

The sacked also include five board directors or executives at five State-owned enterprises, it said.

Government sources said the 10 officials, including Peng Zhiyong, Party chief of Jiulongpo district; Fan Mingwen, Party chief of Bishan county; Han Shuming, deputy Party chief of Changshou district and head of the district government; and Luo Guang, board director of State-owned Southwest Securities Co Ltd, were removed for being involved in the same sex video scandal as Lei.

The municipal government also said that it has busted a criminal ring that used young women to seduce officials and then used secretly filmed sex videos to extort them in 2008 and 2009.

Xiao Ye, one suspect and a key member of the network, and several others, were arrested, as they were accused of arranging for women to seduce those officials and then blackmail them with secretly filmed videos.

Xiao, 45, was the boss of Yonghuang Group in Chongqing, a real estate company that mainly undertakes municipal engineering projects with a total registered capital of 61.7 million yuan ($9.91 million), the Southern Metropolis Daily reported.

Xiao told several women to send text messages to local officials, saying they had met at a dinner and hoped to keep in touch. If the officials returned the messages, the women would occasionally entice the officials with words or photos.

The women later met those officials in high-end hotels in Chongqing for tea or coffee and later in hotel rooms for sex, which was videotaped with hidden cameras.

Xiao closely monitored the progress of relationships between the women and the officials, and would even require reshooting sex videos if they were of poor quality.

In their next date after the video was filmed, several other suspects arranged by Xiao would break into the hotel room to extort the official.

The report said most officials would offer to compromise after seeing the video, and Xiao would step in at this time as a mediator.

Lei had sex with a woman arranged by Xiao in February 2008 and was extorted by Xiao.

Xiao's company later saw its business expand and undertake several real estate projects in Beibei district, where Lei was Party chief at that time.

The report said Lei later decided to confess to the Chongqing Party committee, and authorities ordered a police investigation.

Xiao was given a suspended prison sentence by the court of Shapingba district for "disrupting public order". He was put into a detention center in 2009 and released a year later.

However, the police investigation of the officials did not continue, and those involved in the scandal were not affected in their political career.

Lei's scandal was exposed on Weibo in November and the report said the video was leaked by a Chongqing police officer.

Despite reports that suggested the officials were the victims of entrapment, Liu Shanying, a researcher on political studies at the Chinese Academy of Social Sciences, believed the root of the problem lies with the officials.

"There is an old Chinese saying that says: 'Flies never visit an egg that has no crack'. The criminal suspects could not have succeeded in their plot if the officials didn't have such vulnerabilities," he said.

Liu said the power of supervision by the media and Internet users has been proved in this sex scandal.

"As the case has suggested, real estate and municipal engineering projects are corruption-prone areas, and discipline inspection authorities should work more on these areas," he said.

The sacking of officials in Chongqing was announced one day after Qu Songzhi, Party secretary of the Chengdu branch of the Red Cross Society of China, was removed from her post, the Beijing News reported on Friday.

Qu is the wife of Li Chuncheng, former deputy Party chief of Sichuan province, who was removed from his post for disciplinary violations in December.

Contact the writers at xuwei@chinadaily.com.cn and tanyingzi@chinadaily.com.cn

Xinhua contributed to this story.