Correctional Services said that “matters are under control” at Johannesburg’s Sun City Prison on Wed.
International Criminal Police Organization Secretary-General Ronald Noble hailed the arrest in Singapore last week of 14 suspects.
"I'm confident that Singapore law enforcement authorities have arrested the mastermind and leader of the world's most notorious match-fixing syndicate," Noble said in remarks carried by the city state's Today newspaper.
"It is significant because this syndicate is considered the world's largest and most aggressive match-fixing syndicate, with tentacles reaching every continent and the mastermind was someone many believed was untouchable," Noble was quoted as saying without mentioning any name.
A source has confirmed to AFP that among those arrested was Singaporean businessman Dan Tan, the syndicate's suspected head. He and four others are now being held without bail under a tough law designed for criminal gang members.
The Straits Times newspaper quoted Noble as saying that the arrests were the result of cooperation between Singapore and Interpol's Global Anti-Match-Fixing Task Force.
The Interpol chief spoke to the local media after attending a ceremony for the construction of an Interpol complex in Singapore.
The European police agency Europol in February said it had smashed a network rigging hundreds of games, including in the Champions League and World Cup qualifiers.
Europol said at that time that a five-country probe had identified 380 suspicious matches targeted by a Singapore-based betting cartel, whose illegal activities stretched to players, referees and officials across the world.
Tan, whose full name is Tan Seet Eng, has denied involvement in match-fixing.
"Why I'm suddenly described as a match-fixer, I don't know. I'm innocent," he told Singapore's The New Paper in 2011 in his only known media interview.
Tan, however, has a standing warrant for his arrest issued by Italian investigators over the wide-ranging "calcioscommesse", or football betting, scandal, which implicated a swathe of big names and clubs.
In May, Tan was also charged in Hungary over the alleged manipulation of 32 games in three countries.
Match-fixing has proved a chronic and growing blight on football and it hit the headlines again this month after six men were charged over a multi-million dollar scam in Australian state soccer.
In the latest case within Singapore, three Lebanese referees were convicted in June of accepting sexual services in return for fixing future games.
The trial of a Singaporean businessman linked to the referees' case, 31-year-old Eric Ding Si Yang, is continuing.