Chinese soccer has been rocked again with top officials of the sport's ruling body under investigation amid the nationwide clampdown on gambling and match fixing.

Nan Yong, vice-president of the Chinese Football Association (CFA) was taken for questioning on Friday night, the Ministry of Public Security (MPS) said yesterday.

Yang Yimin, another CFA vice-president, and Zhang Jianqiang, the women's soccer chief who was also in charge of referee arrangements, were also taken to the police station.

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

Meanwhile, Jia Xiuquan, former head coach of the national Olympic team and Shanghai Shenhua in the Chinese Super League (CSL), was also taken by the police for questioning last week, Beijing News reported.

Local media thronged to the CFA office in Beijing yesterday but were kept out by tight security.

Link to sponsor, selection of host cities

The investigation is the most high-profile since a campaign began last August to eradicate the blight of gambling and match-fixing, which are believed to be the main reason behind the sport's struggles.

Nan and Yang were reportedly called to the State General Administration of Sport (SGAS), the nation's top governing body, to attend an urgent meeting but found police waiting for them in the office.

They haven't been seen at their CFA offices after they left for the SGAS office, and their cars were yesterday still seen in the SGAS parking lot.

No specific evidence of Nan's involvement has been revealed but police have sealed his office, and temporary replacements have been named for his and Yang's posts.

Nan, 47, who took over as CFA vice-president last January, is reportedly suspected of being involved in a long-time financial row with the former title sponsor of CFL, British company Iphox, according to Soccer News.

Nan was in charge of the contract signing but did not take action after the company failed to pay more than 50 million yuan ($7.3 million) in the stipulated time.

The money is still unpaid.

He has also been linked to the selections of host cities for Chinese team's international matches. He reportedly used his power to allot matches to associations with good connections to him.

The CFA has long been slammed for its lack of effort in dealing with problems in the CSL, the nation's top-flight league.

It was even targeted by some fans and the media for allegedly playing a supporting role in the deterioration of the scandal-ridden league.

Police reportedly visited the SGAS office for investigation in November, shortly after President Hu Jintao, Vice-President Xi Jinping and State Councilor Liu Yandong made remarks about the need to revitalize the sport.

So far, more than 100 current and former players, coaches, referees, club officials and industry insiders have been questioned.