A small but select number of alleged breaches by NAB of credit law may convert into hundreds of millions of dollars in penalties, at the extreme, if a civil claim bought by ASIC on Friday has merit.The affair centres on one of the better known "scandals" that have dogged NAB over recent years, and the litigation will help define an end point to it all.ASIC's complaints "relate to the conduct of 16 bankers accepting loan information and documentation from 25 unlicensed introducers in relation to 297 loans".This is pretty slight in the context of the overall reach of the program, described at length in the interim report of the banking royal commission last year.In that report, commissioner Kenneth Hayne noted "the Introducer Program has been a profitable source of lending for NAB, resulting in more than $24 billion in loans between 2013 and 2016."At its peak, there were approximately 8000 Introducers in the program."In late 2015, following two tip-offs from whistle-blowers, NAB engaged KPMG to dig into the pitfalls of a program with origins in the early 2000s. Frank Cicutto was the bank CEO at the time the bank invented this now discredited mortgage sales method.As Hayne's report noted: "NAB acknowledged that between 2013 and 2016, NAB bankers in the Greater Western Sydney area and in other parts of NSW, the ACT and Victoria, engaged in misconduct in connection with home loan applications submitted through the NAB Introducer Program."ASIC is asking the Court to find that NAB breached the National Consumer Credit Protection Act 2009 and to impose a civil penalty on NAB for doing so. The maximum penalty for one breach of the National Credit Act, during the time of contravention, was 10,000 penalty units, or A$1.7 to $1.8 million, ASIC said in its media release.AFR columnist Tony Boyd took a punt at the weekend that NAB might well opt for a speedy commercial settlement, with Daniel Crennan, ASIC's deputy commissioner, telling Boyd the case "could be resolved quickly" if NAB decides to negotiate an outcome agreed to by both parties.Given the ample evidence turned over by the royal commission, NAB won't have much of a defence.As Hayne wrote: "As a result of investigations, 10 bankers were dismissed, 10 areno longer with NAB and 32 had 'internal consequences' applied, such as reduction of their incentives."A number of the bankers involved in the conduct, including a number of those who were dismissed, were branch managers."In some instances, the conduct identified resulted in loans being made by NAB that were later found to be unsuitable."In March, NAB announced that it will be terminating the Introducer Program from 1 October.ASIC's claims against NAB will be heard in the Federal Court of Australia in Sydney.