He has been ordered to surrender his passport.
Four of his co-accused were also released on bail.
Mr Agrizzi, a former chief operations officer of Bosasa, recently blew the lid on the alleged corruption at a judge-led inquiry.
The company, now re-branded African Global Group, had won lucrative catering, facilities management and security contracts at various government institutions.
An anti-corruption whistleblower is among six people people arrested in South Africa over the alleged illegal awarding of tenders by the prison department to private firm Bosasa, local media report.
Former Bosasa chief operations officer Angelo Agrizzi blew the lid on the alleged corruption during days of riveting testimony at a judge-led inquiry - only to be now arrested along with people he implicated.
They include former prison boss Linda Mti, according to local media.
South Africa's elite anti-corruption unit, the Hawks, arrested the six on allegations of corruption, including fraud and money-laundering, in connection with the awarding of tenders worth 1.6bn rand ($118.7m, £91.6m) to Bosasa and companies linked to it, the privately owned TimesLive news site reported.
Legal representatives of the six have not yet commented.