"It would gave been optimistic to think that none of the offenders would relapse into crime," Ndebele told a media briefing by government's justice, crime prevention and security cluster.

Ndebele said the decision by President Jacob Zuma to pardon the prisoners, who were serving sentences for crimes such as theft and fraud, was motivated in part by a desire to combat over-crowding of 34% in South Africa's jails.

He said it would also be idealistic to think that all prisoners had benefited from rehabilitation programmes.

Justice Minister Jeff Radebe confirmed that 71 of the prisoners had been re-arrested and convicted, but said the figure amounted to 0.18% of those released and was "very negligible".

According to figures cited by Radebe, 17 556 prisoners were actively involved in correctional programmes, out of a prison population of 167 819.

The justice minister told reporters that crime levels dropped in the first quarter of this year, while the state's conviction rate had increased.

He said serious crimes decreased by 0.5% from January to March, compared to the same period last year, while contact crimes had decreased by 1.2%.

Radebe said the courts' conviction rate on so-called trio crimes --hijacking and business and home robberies -- reached 85.8% of 1 777 cases finalised.

The minister dismissed a journalist's observation that the number of cases finalised were roughly ten percent of those reported, leaving most perpetrators free.

He said the courts also finalised 192 cases of organised crime and achieved an 89% conviction rate.

The Asset Forfeiture Unit froze criminal assets of more than R540 million last year, while, as part of the drive against rhino poaching, the National Prosecuting Authority convicted 28 people.

Radebe said the department was making sexual crimes a priority, and the task team looking into the viability of reopening the sexual offences courts would also mull ways of ensuring these courts had greater reach.

"The task team will look into practical steps that will ensure that these courts benefit the entire population and not selected communities as was the practice in the pilot sites."