For the First Part of your querry, it is quite settled law that action under 340 C.r.p.c could be initiated after the false evidence tendered in the court. The Hon'ble Supreme Court in Iqbal Sing Marwah V. Meenakshi Marwah, 2005 (4) SCC 370 and held that "Section 195(1)(b)(ii) CrPC was attracted only when the offences, enumerated in the said provision have been committed with respect to a document after it has been produced or given in evidence in any court during the time the same was in custodial legis". Also, Delhi High Court in Arun Dhawan & Anr vs Lokesh Dhawan held that "even if a document was tampered/forged prior to institution of the legal proceedings, the Court will have jurisdiction to entertain an application under section 340 of the code if the document has been produced in Court proceedings. Further it is laid down that making of false averment in the pleading pollutes the stream of justice. It is an attempt at inviting the Court into passing a wrong judgment and that is why it must be treated as an offence. Where a verification is specific and deliberately fals e, there is nothing in law to prevent a person from being proceeded for contempt." Therefore, application under Section 340 C.r.p.c will be maintible if evidence has been tendered in court.
As far as second part of your querry is concerened, Witness can file a thretening complaint and witness must do so. There is a specific provision which makes threatening a witness to give false evidence a penal offence.
For further queries contact undersigned.
P.S.- Please ignore the above formatting errors.
Regards,
Advocate Nitin Kapoor
Mob: 8800692624.