Police have summoned three high-ranking officials of China's soccer association to help with an investigation into match-fixing and gambling scandals, Ministry of Public Security (MPS) announced Thursday.

Police in Liaoning Province summoned Nan Yong and Yang Yimin, both vice chairmen of the Chinese Football Association (CFA), and Zhang Jianqiang, former director of the association's referee committee, said a statement released by the MPS.

"With the full support from the sports department, the crackdown on manipulating domestic soccer matches through commercial bribery has showcased a firm attitude in fighting corruption and rectifying the soccer sector," said the statement.

"The crackdown also gives us confidence and hope to revitalize the development of Chinese soccer," it said.

Officials with the CFA's headquarters in Beijing either remained silence or refused to comment on the ministry's statement but confirmed that the two vice chairmen had not appeared in the association's building since Monday.

At an internal meeting of the CFA held on Wednesday, two other vice chairpersons Xue Li and Lin Xiaohua officially took over the jobs of Nan and Yang.

This was the third time the ministry released details of the ongoing nationwide probe into match-fixing and gambling scandals exposed in China's soccer leagues.

Last November, the MPS said at least four people had been detained for suspected bribery. In December, police made more arrests, including You Kewei and Xu Hongtao, two former leaders with Chengdu Blades Football Club in China's A-level Football League.

Preliminary investigation showed that the Chengdu Blades FC, which has been held by England Sheffield United FC, were suspected of bribing their rival Qingdao Hailifeng FC to manipulate an A-level league game on Sept. 22, 2007. The Blades won the match 2:0.

The victory helped upgrade the Blades into China's top soccer league, Chinese Super League, after the 2007 season. And Liu Hongwei, the former team leader of the Hailifeng FC who is suspected for taking the bribe, was also arrested.

Last month, Nan Yong said after the ministry publicized the Blades-Hailifeng scandal that soccer gambling and match-fixing should be wiped out, pledging that the CFA would provide full cooperation for police investigation.

He also said the probe into soccer scandals would be deepened and the association would punish the corrupt clubs in line with regulations.

"I hope police can dig out the crux of the problem that obstructs the development of Chinese soccer, and come up with satisfactory answers for the fans," said Xu Jiali, a lawyer with the discipline committee of last season's CSL.

The police crackdown began in March 2009 when a high-profile committee was set up by 12 ministry-level organs to clean up corruption in Chinese soccer.

Last October, President Hu Jintao, Vice President Xi Jinping and State Councilor Liu Yandong stressed the need to revitalize soccer in China.