Both Michael Norman and David Bannister were supposed to testify for the State against Broadway on Tuesday in the Western Cape High Court.
Broadway, who is conducting his own defence, has pleaded not guilty to the charges.
Prosecutor Quinton Appels told Judge Siraj Desai the matter would not be able to proceed because of the two key witnesses’ unwillingness to testify.
Norman said: “Your honour, I cannot testify because I have been threatened. I don’t know the person who made the threats, but he mentioned the names of my family.”