Sun International was "extremely grateful" that four of its employees had been released from detention in Nigeria, the company said in a statement on Tuesday.
"Sun International confirmed that it had secured the release of four employees late last night, who had been detained without charge in Nigeria by the Economic and Financial Crimes Commission (EFCC) since Thursday 21 January."
The EFCC still intended investigating Sun International's investment into the Tourist Company of Nigeria (TCN), and had asked for TCN's trading records and other documentation.
The company said it would work with the TCN to give the EFCC the information it wanted.
Sun International said it was grateful to various South African government agencies, in particular the South African High Commission in Nigeria, for helping to secure the release of the four.