Travelling to sa as single parent with child

Hi,

I am travelling to SA next week and may well have to travel without my fiancée. I will need to enter SA with my child without her.

Details
Not Married - and therefore different surname
I am the Father and have duel citizenship with UK and SA
My child is 7 months old today and is only a British citizen.
3 to 4 week trip

I phoned the SA home affairs and was told that the only way I could go into SA with my child would be to register him as a South African!!!

This cant be true cant it?

I thought I would need some sort of letter from his mother.

Who else has had this situation and how did you deal with it?

Many Thanks

Thanks - We have got a letter of consent and I will take that with me. Hopefully all will be ok.

Not sure what will happen at the boarder post as I will have to go through the SA Citizen bit myself, but my son will need to go through the foreign section - I assume they can do both me and my son at the SA border desk even though he only has a British passport - This must happen a lot.

Thanks.