The US Embassy says it has received reports of an “incident” involving an American citizen at the private park.
The embassy said in a statement that it has no information, but will follow up to “provide any assistance possible”.
EWN, a South African news outlet, cites park officials as saying a tourist died in a lion attack.
The Lion Park is a popular destination for tourists who can drive in their own vehicles through large enclosures where lions roam freely. Visitors can also pet lion cubs in smaller pens.