The Mpumalanga Tourism and Parks Agency's (MTPA) CEO has refused to accept his suspension and is back at work.
"Pinky Phosa [MEC for economic development, environmental affairs and tourism] told me in a letter this morning [Wednesday] that the board cannot do this. I am the executive head and I must return to work," Jacques Modipane was quoted as saying, in a Beeld newspaper report.
"According to the law I have a choice and I say no."
Acting MTPA board chairwoman Clara Ndlovu removed Modipane from his post last Thursday after about 40 rhino horns were stolen from the organisation's safe. News agency Agence France-Presse reported the horns could be worth up to US16 million (around R170m).
According to Modipane the MTPA board is gunning for him after he fired several high-ranking employees in a bid to root out corruption.
MTPA spokesman Kholofelo Nkambule said no arrests had been made in connection with the rhino horn theft.