"26. In light of these extracts, we are in agreement with the respondent claimant that the presumption mandated by Section 139 of the Act does indeed include the existence of a legally enforceable debt or liability. To that extent, the impugned observations in Krishna Janardhan Bhat [(2008) 4 SCC 54 : (2008) 2 SCC (Cri) 166] may not be correct. However, this does not in any way cast doubt on the correctness of the decision in that case since it was based on the specific facts and circumstances therein. As noted in the citations, this is of course in the nature of a rebuttable presumption and it is open to the accused to raise a defence wherein the existence of a legally enforceable debt or liability can be contested. However, there can be no doubt that there is an initial presumption which favours the complainant.

27. Section 139 of the Act is an example of a reverse onus clause that has been included in furtherance of the legislative objective of improving the credibility of negotiable instruments. While Section 138 of the Act specifies a strong criminal remedy in relation to the dishonour of cheques, the rebuttable presumption under Section 139 is a device to prevent undue delay in the course of litigation. However, it must be remembered that the offence made punishable by Section 138 can be better described as a regulatory offence since the bouncing of a cheque is largely in the nature of a civil wrong whose impact is usually confined to the private parties involved in commercial transactions. In such a scenario, the test of proportionality should guide the construction and interpretation of reverse onus clauses and the defendant-accused cannot be expected to discharge an unduly high standard or proof."

2010 SCeJ 001 Rangappa v. Sri Mohan, (2010) 11 SCC 441