Hundreds of mainland soccer officials, referees and coaches were sent to 'anti-corruption rectification education camps' in Beijing and Guangdong yesterday as the authorities seek to clean up the sport. More than 200 top referees were told a three-day boot camp that started in Beijing was their last chance to turn themselves in in return for more lenient treatment. 'We are giving those in trouble a chance of self-redemption,' Xinhua quoted the new chief of the China Football Association, Wei Di , as saying on Thursday. Wei urged officials, referees and others caught up in match-fixing and corruption to 'come clean and confess' in exchange for leniency and warned that those caught after the grace period would be punished. Head coaches of most of the national soccer teams began a similar three-day camp in Sanshui , Guangdong. The coaches received skills training earlier in the week from prominent coaches including Kwok Ka-ming, Hong Kong's head coach from 1982 to 1990. Kwok guided his team to a famous victory over China in 1985, knocking them out of contention for the World Cup finals - an event that sparked rioting in Beijing. The mainland coaches began by focusing on anti-corruption and rectification education yesterday, the Guangzhou-based Yangcheng Evening News reported. Soccer has been under the microscope since the second half of last year, when President Hu Jintao and Vice-President Xi Jinping ordered sports authorities to clean up corruption and match-fixing. Xi also vowed to improve the competitiveness of national teams. Hong Kong is also looking to improve the standard of soccer, with a government consultancy study released this week outlining a HK$75 million to HK$100 million plan for the Hong Kong team to climb into the world's top 100 in the next five years. It is currently ranked 143rd. According to a training schedule published by mainland media, the referees in Beijing met leaders of the China Football Association yesterday, then broke up into small groups to discuss the problems they are facing. They will have a test today and will be asked to sign a letter of commitment tomorrow, pledging to oppose corruption. The 210 male and female referees at the camp will also have individual talks with CFA leaders. Wei described the camps as a chance for all CFA officials, referees, and others involved in match-fixing and corruption to come clean. 'Party policy is always 'to confess is to be punished leniently',' he said. The association and anti-graft officials from the State General Administration of Sport had evidence suggesting that some mid-level CFA officials could have been involved in corrupt activities, Wei said. He confirmed that three referees - Lu Jun, who refereed at the World Cup finals in 2002, Huang Junjie and Zhou Weixin - had been taken away by police for investigation. Lu has twice been recognised as Asia's top male referee, in 1998 and 2004. The crackdown on graft in the game has brought down some big names. Nan Yong and Yang Yimin, former vice-chairmen of the association, and Zhang Jianqiang, former director of its referees' committee, were arrested for match-fixing and bribery this month.