A lioness became aggressive towards the other and then turned her attention to the conservationist affectionately known as “Uncle West”, reports the BBC’s Nomsa Maseko from Johannesburg.
His relatives have said that Wednesday’s attack could have been the result of very rough play.
The lionesses were tranquillised following the attack and have been taken to an endangered species centre.
Mr Mathewson is said to have rescued the lions from “canned hunting” – when animals are hunted in an enclosed area, or they are bred to be hunted – and they were kept in an enclosure at his lodge.
The lionesses reportedly killed a man working on a neighbouring property after they broke out of the enclosure in 2017.
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Media captionAre people hunting ‘canned lions’ in South Africa?