South African cricket is bracing itself for its biggest match-fixing scandal since the Hansie Cronje affair as the International Cricket Council's anti-corruption unit closes in on a former South Africa Test player thought to be the ringleader of attempts to corrupt the recent Ram Slam Twenty20 competition.

Investigators from the ACU have been working for weeks on a complex case that is expected to become public once the Test series against England is completed.

Former South African captain, the late Hansie Cronje, at his cricket corruption hearing in 2000. Credit:Andrew Ingram

The case will be a huge test for Cricket South Africa and the ICC, which is helping the local authorities with their investigation.

CSA has declined to comment apart from releasing one statement on December 16 announcing that it had suspended an "intermediary" with "contriving to fix, or otherwise improperly influence aspects" of the Ram Slam, South Africa's domestic Twenty20 competition.