remedy when evidence tampered by IO or the original complainant

Tampering with evidence is closely related to the legal issue of spoliation of evidence, which is usually the civil law or due process version of the same concept (but may itself be a crime). Tampering with evidence is also closely related to obstruction of justice and perverting the course of justice, and these two kinds of crimes are often charged together. The goal of tampering with evidence is usually to cover up a crime or with intent to injure the accused person.

Elements of the Offence - 

• Intention 
• Knowledge 
• Substance tampered must be 'evidence'
• Awareness of a Potential or Pending Investigation

Penalty - 
Section 204 of IPC states that —Whoever secretes or destroys any 1[document or electronic record] which he may be lawfully compelled to produce as evidence in a Court of Justice, or in any proceeding lawfully held before a public servant, as such, or obliterates or renders illegible the whole or any part of such 1[document or electronic record] with the intention of preventing the same from being produced or used as evidence before such Court or public servant as aforesaid, or after he shall have been lawfully sum­moned or required to produce the same for that purpose, shall be punished with imprisonment of either descripttion for a term which may extend to two years, or with fine, or with both.

The accused's counsel may even contest for mistrial.