A dead man statute is a law to prevent perjury or fabrication of evidence in civil case by preventing an interested witness from testifying on communications or transactions with a deceased.
Though there is no federal law imposing such restriction yet almost about half of the states have a dead man statute in force.
This restriction applies against a witness who has an interest in the results of the proceedings and who is deposing for his self interest and against the interest of the deceased. This embargo operates only in civil cases and never in criminal cases.
However, this restriction may be waived only when the testimony of the deceased is brought on record in the form of a deposition.