South Africa's bid to have two brothers from the wealthy Gupta family extradited from the United Arab Emirates (UAE) has failed.
Atul and Rajesh Gupta are accused in South Africa of profiting from their close links with former President Jacob Zuma and exerting unfair influence.
The justice ministry said it had learnt with "shock and dismay" about the move.
The brothers, who deny any wrongdoing, fled after a judicial commission began probing a major corruption scandal.
The Indian-born Guptas were arrested in the UAE last June and extradition talks with South Africa began.
But the UAE said that it turned down the extradition request on a technicality.
In a brief statement, quoted in the Emirates News Agency, it said that a review "found that the request did not meet the strict standards for legal documentation as outlined in the extradition agreement between the UAE and South Africa" that came into force two years ago.
Some of the paperwork was either incorrect, in the case of the fraud charge, or missing, in the case of the corruption charge, the statement adds.
The decision was made in February but it was only communicated to South Africa on Thursday, South African Justice Minister Ronald Lamola said.
"The reasons provided for denying our request are inexplicable and fly in the face of the assurances given by Emirati authorities that our requests meet their requirements," Mr Lamola is quoted by South Africa's Mail & Guardian newspaper as saying.