Dutch language class (Dar es Salaam)

Dear expats,
Last octobre I married my tanzanian husband. For immigration procedures he needs to do a dutch language exam.
Is there anyone who can help us to get in contact with dutch people living in Tanzania who can help my husband with dutch language class?
He has a package of study materials. He is flexible to travel between Bukoba/Mwanza and Dar Es Salaam and speaks both kiswahili and english.
Kind regards, Lieveke