Compulsory registration of agreement of unsurveyed plot

Two years back I bought a piece of unsurveyed plot in my home town. This year somebody encroached into my plot and began constructing a house on it. I instituted a suit against him in Court but on the date of hearing when I sought to tender the sale agreement, his advocate raised an objection that my sale agreement should not be admitted because it was not registered by the registrar of documents. I would like to know if there is any law which requires an agreement pertaining to the sale of unsurveyed plot to be registered. 
RT, Arusha

A sale agreement of unsurveyed plot other than a plot held under customary law is compulsorily registrable under section 8 of the Registration of Documents Act [Cap.117 R.E 2002]. In view of section 9 of the Act, failure to register a sale agreement of unsurveyed plot other than a plot held under customary law has two effects. One, the title or interest in the plot does not pass to the buyer. Two, the sale agreement as a documentary evidence becomes inadmissible in Court for want of proof of registration.

Registration of sale agreement of unsurveyed plot is a pre-condition for its admissibility as evidence in Court. A party seeking to produce such a sale agreement as an exhibit in Court proceedings has the burden of proving to the Court that the sale agreement was registered by the registrar of title for the document to qualify for admission as a documentary exhibit. The absence of proof of registration of the sale agreement by the registrar of documents renders the document inadmissible. If you did not register the sale agreement, it is likely to be rejected by the Court under section 9 of the Registration of Document Act.