1The following persons shall not be questioned as witnesses:
apersons who, due to physical or mental disabilities, are not able to render regular testimony;
bpersons co-accused of the same offence or accused in joint proceedings, if a decision of non-initiation of the proceedings, dismissal or conviction has been issued against them, including the cases of plea bargaining and criminal order of conviction, except for the cases when the decision of acquittal has become final;
cthe persons who in the same proceedings perform or have performed the function of judge or prosecutor;
çthe civil defendant and the person with civil liability for the damages caused by the defendant.
2The rule provided for under letter “b”, of paragraph 1, does not apply for the collaborator of justice, who is always questioned as a witness, pursuant to Article 36/a of this Code.