How to prove that you have assets to your sponsor's funds?

[Chibuzor8888]

The sponsor is my uncle, so how do I prove that I have access to the funds in his account?

 

[Naturgrl]

The sponsor is my uncle, so how do I prove that I have access to the funds in his account?

He provides his account details from his personal accounts. Or he provides a notarized gift deed.