Section 229: Exclusion of evidence to contradict answers to questions testing veracity.

When a witness has been asked and has answered any question which is relevant to the inquiry only in so far as it tends to shake his credit by injuring his character, no evidence shall be given to contradict him, but if he answers falsely he may afterwards be charged with an offence under section 191 of the Criminal Code and on conviction, shall be dealt with accordingly;
Provided that if a witness is asked-
a whether he has been previously convicted or any crime and denies it, evidence may be given on of his previous conviction; or
b any question tending to impeach his impartiality and answers it by denying the facts suggested, he may be contradicted.