The Supreme Court in the case of State (Delhi Administration) vs Sanjay Gandhi, 1978 AIR 961, 1978 SCR (3) 950.

“Before we go to the facts of the case, it is necessary to consider what precisely is the nature of the burden which rests on the prosecution in an application for cancellation of bail. Is it necessary for the prosecution to prove by a mathematical certainty or even beyond a reasonable doubt that the witnesses have turned hostile because they are won over by the accused ? We think not. The issue of cancellation of bail can only arise in criminal cases, but that does not mean that every incidental matter in a criminal case must be proved beyond a reasonable doubt like the guilt of the accused. Whether an accused is absconding and therefore his property can be attached Under Section 83 of the Criminal Procedure Code, whether a search of person of premises was taken as required by the provisions of Section 100 of the Code, whether a confession is recorded in strict accordance with the requirements of Section 164 of the Code and whether a fact was discovered in consequence of information received from an accused as required by Section 27 of the Evidence Act are all matters which, fall peculiarly within the ordinary sweep of criminal trials. But though the guilt of the accused in cases which involve the assessment of these facts has to be established beyond a reasonable doubt, these various facts are not required to be proved by the same rigorous standard. Indeed, proof of facts by preponderance of probabilities as in a civil case is not foreign to criminal jurisprudence because, in cases where the statute raises a presumption of guilt as, for example, the Prevention of Corruption Act, the accused is entitled to rebut that presumption by proving his, defence by a balance of probabilities. He does not have to establish his case beyond a reasonable doubt. The same standard of proof as in a civil case applies to proof of incidental issues involved in a criminal trial like the cancellation of bail of an accused. The prosecution, therefore, can establish its case in an application for cancellation of bail by showing on a preponderance of probabilities that the accused has attempted to tamper or has tampered with its witnesses. Proving by the test of balance of probabilities that the accused has abused his liberty or that there is a reasonable apprehension that he will interfere with the course of justice is all that is necessary for the prosecution to do in order to succeed in an application for cancellation of bail.”