At least four people have been detained on suspicion of match-fixing and underground betting during a crackdown on soccer corruption.

The Ministry of Public Security announced yesterday that a number of former players, soccer officials and club officials had been detained. The detainees include Wang Xin, Wang Po, Ding Zhe and Yang Xu. They are suspected of "manipulating domestic soccer matches through commercial bribery".

Some of those in custody are also suspected of gambling through foreign websites, the ministry said.

It was the first time the senior law and order ministry had spoken about the massive investigation into soccer-related crime.

The crackdown is believed to be in response to growing frustration at the highest level of government about the ugly state of the "beautiful game" in China.

According to the ministry, Wang Xin, a former player from Liaoning province who later became general manager of Singapore-registered Liaoning Guangyuan club, was a key person for police in discovering the under-the-table betting and fixing in the sport.

Wang Xin was wanted by Interpol in Singapore at the start of the year after he fled the country after his team's match-fixing scandal was exposed. He was arrested in Liaoning in April, police said.

Police said Wang Xin, together with former Shanxi club general manager, Wang Po, was suspected of manipulating several First Division league matches since 2006. The First Division is the second tier league in China.

Also dragged in the match-fixing scandal was current Chinese Super League team Guangzhou Pharmaceutical FC, which was promoted from the First Division in 2007.

Police claimed Yang Xu, former deputy manager of the Guangzhou club, once paid 200,000 yuan ($29,000) to Wang Xin and Wang Po for a 5-1 win in 2006.

However, the match-fixing exposed so far is believed to be only the tip of the iceberg.

"There have been secret rules in Chinese soccer," said Yang, who was also the former vice-president of the Guangzhou Football Association.

"I thought since everyone was doing that (bribing and manipulating matches), we would suffer for our honesty if we didn't follow the practice. I know it was wrong but I thought we could get away with it."

While the country has improved in the sporting arena and topped the medal table at last year's Beijing Olympics, soccer has proven the exception.

The performances of the national team have lurched from bad to worse, and the league has struggled to shake off the cloud of match-fixing and corrupt referees - known as "black whistles".

In the past month, President Hu Jintao, Vice-President Xi Jinping and State Councilor Liu Yandong each commented on the need to revitalize soccer.

On Sunday night, six players from the national soccer team were summoned by State Council investigators for a late-night meeting in Hangzhou, Zhejiang province.

The players said they were not being investigated but claimed they were asked to offer advice on how to improve the dire state of soccer, local media reported.

While the government is soliciting ideas, the police department is conducting the biggest judicial intervention into the sport so far. And the ministry yesterday promised to carry it forward.

In the past decade, there has been sporadic cooperation between the Chinese Football Association and police but the efforts have yielded few meaningful results.

Experts have said they hope the crackdown will have a lasting effect and called for a better supervision mechanism and legislation.

Liu Liang, a law professor with China Criminal Police College, suggested setting up specific charges for match-fixing and sports gambling within the Criminal Law.

Liaoning-based lawyer Lei Yubo said, under the Criminal Law, soccer gamblers could be charged for "gambling", which could lead to a sentence of up to 10 years. "Considering the huge amount of money involved in soccer gambling, the sentence is too light," he said.