According to a The Sun UK report, Sifiso broke his neck after trying to perform the trick at a competition in South Africa on 5 August.
The over-75kg world champion had been playing to the crowd before a contest on Saturday.
He was filmed stepping onto the mat before gesturing to the crowd and launching himself into the air but he was unable to flip over and instead landed on his head in the horror footage being shared online.
Mr Thabete’s funeral which held on Wednesday had fans saying he will always be missed.
See video below