The police detained the man, who is considered a "high value individual", on Tuesday in Cork Trust village, South African National Parks (SANParks) spokesperson Ike Phaahla said on Wednesday.
"The arrested individual … is suspected of being part of an active group of poachers operating in the Kruger National Park and surrounding reserves," said Phaahla.
Police recovered what was believed to be rhino body parts, a SANParks field ranger's uniform, hunting equipment, guns and ammunition.
Three alleged poachers were arrested in a separate incident after a shoot-out with rangers in the Malelane section of the Kruger Park. One of the alleged poachers was shot and wounded.
The police recovered weapons and hunting equipment.