Oscar Pistorius leaves on bail from the North Gauteng High Court on September 12, 2014 in Pretoria, South Africa© Mirrorpix / Splash News Oscar Pistorius leaves on bail from the North Gauteng High Court on September 12, 2014 in Pretoria, South Africa

Oscar Pistorius’s release from prison was delayed on Wednesday night after the South African justice minister made a surprise last-minute intervention in the controversial case.

The 28-year-old had been expected to walk free from a prison in Pretoria on Friday, to see out the rest of his sentence for manslaughter under house arrest.

The early release caused widespread anger – including from the family of Reeva Steenkamp, who was shot dead by the sprinter on Valentine’s Day 2013. But Michael Masutha, the justice minister, said his decision had “nothing to do with the fact that it’s a high-profile matter”.

He said that he was seeking legal advice on whether the parole board was right to release Pistorius on house arrest after 10 months – or one sixth of his five-year sentence. Mr Masutha said that a request for his release was considered and approved in June – only eight months into the sentence.

“It is apparent therefore that the decision to release him on 21 August 2015 was made prematurely on 5 June 2015, when the offender was not eligible to be considered at all,” the justice department said in a statement.

Mr Masutha later defended his decision on television.

“I’ll tell you what concerns me most is that if we say this is the law, we must be sure that this indeed is the law, because it would be egg on our face if it turns out that actually we’ve misinterpreted the law,” he said.

“My starting point is upholding the rule of law. That’s what the constitution requires.”

A parole board will now review the matter.

The Olympic athlete was sentenced in October 2014 to five years for manslaughter after shooting dead Steenkamp.

The double-amputee athlete, known as the “Blade Runner” because of the carbon-fibre prosthetics he used on the track, was scheduled to be released from Pretoria’s Kgosi Mampuru II Prison on 21 August – a decision which sparked anger among some in South Africa.

But the petition against his release, filed by rights groups last week to the justice minister, may have scuppered his release.

“To let him out two days after Reeva’s birthday, during a time when South Africa is celebrating women’s month is an insult,” said Jacqui Mofokeng, spokesman for the ANC Women’s League. “It is insensitive, especially with all the problems we have here with violence against women.”

A family member told Reuters that they were “shocked and disappointed” the athlete will not “be home” on Friday.