Evidence procured by illegal means
Even if a document is procured by improper or illegal means, there is no bar to its admissibility if it is relevant and its genuineness is proved.
A forged letter used to make complaint:
A letter dated 22.4.2011 purported to have been written by Shri M.A. Khan, M.P., suggests that various properties had been purchased by respondent no.2 as benami and the copies of the sale deeds etc. filed alongwith the said letter fortify the same. The Government of India wrote a letter to the Chief Secretary, Govt. of A.P. on 5.5.2011 to conduct an enquiry in respect of alleged disproportionate assets made by the respondent no.2 by purchase of huge lands either by himself or in the name of his wife or through benamis. Shri M.A. Khan, M.P. vide letter dated 23.5.2011 pointed out to the Central Government that he had not signed the complaint and his signature had been forged.
Conclusion of Supreme Court permitting illegal evidence:
If the evidence is admissible, it does not matter how it has been obtained. However, as a matter of caution, the court in exercise of its discretion may disallow certain evidence in a criminal case if the strict rules of admissibility would operate unfairly against the accused. More so, the court must conclude that it is genuine and free from tampering or mutilation. This court repelled the contention that obtaining evidence illegally by using tape recordings or photographs offend Articles 20(3) and 21 of the Constitution of India as acquiring the evidence by such methods was not the procedure established by law.
Mystery of Law and Justice 