Ref. No. 41/1067
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
We consulted some ulama of South Africa and came to know that Mufti Ahmed Sadiq Desai is one of the followers of Deoband school of thought, though he is a bit harsh in his language.
And Allah knows best
Darul Uloom Waqf Deoband