Its a basic rule of law that party to any suit/case as the case may be,has right to produce any witness who may proove his case...here the statement of accused was witnessed by any person,he may be examined by prosecution whether his/her name is mentioned/not mentioned in charge sheet....
A statement under section 161of CrPC is not a mandatory pre-requiste for a witness to be examined in a criminal trial.
As accused is provided copy of police report and other documents,u/s 207 of cr.p.c.,he had copy of his confessional statement,and he can be cross examined by accussed....
Indian Evidence Act also provides that any witness who is competent to give evidence can be produced as witness u/s118