Defence witness is as good as prosecution witness. Defence witness should be appreciated as court appreciate the prosecution witness. Court should come out from the view that defence witness are always false and come to help the accused. Means equal treatment should be given to defence witness. for the same you may refer the following citations.
1984(3) Crimes Page 209 Guj.
2000(2) Crimes 29 SC,
1981 Criminal Law Journal Page 618 = AIR 1981 SC 911,
1993 (2) Crimes 1022.
Actually, the prosecution i.e. state has to bear the expenses for calling the defence witness.
Defence witness can produce the documents. As the law of equalilty you should provide the documents to the prosecution though there is no specific provision in Cr. P. C.
I think it will clear the things after going through the citations.
Kirit A. Mehta.