Shareholders this week will quiz National Australia Bank chairman Ken Henry about shortcomings in the bank's compliance with anti-money laundering laws.NAB buried a disclosure about "weaknesses" and "issues" with its anti-money laundering systems on page 108 of the 2017 annual report.The bank revealed a contingent liability after it identified weaknesses in transaction monitoring and Know Your Customer rules.The Australian Shareholders' Association will be looking to raise the matter at the company's annual meeting in Sydney on Friday.ASA spokesman Dennis Shore said his organisation wanted to find out more about the potential compliance problems and whether they could potentially undermine shareholder value."We will ask the chairman to provide more detail on the contingency to establish whether the bank is exposed to penalties," he said."It would be useful if the chairman could give some comfort to shareholders that the weaknesses and issues don't constitute breaches of anti-money laundering and counter-terrorism laws."NAB warned in its annual report that a special internal investigation focused on its anti-money laundering procedures could unearth "further issues".There is evidence to suggest that the bank may have been inconsistent in its disclosure about the compliance problems.In the latest annual report the bank said it began investigating its anti-money laundering processes in July 2016, saying the program involves "significant investment in systems".That assertion might be inconsistent with statements made on page 24 of NAB's half-year accounts published on 4 May, where the bank said it had "reduced spend on regulatory reporting, anti-money laundering and Basel III" in the six months to the end of March.The other potential disclosure problem concerns comments made by NAB chief executive Andrew Thorburn to a House of Representatives committee in October.When asked whether NAB was compliant with anti-money laundering laws by the parliamentary committee, Thorburn said "yes", adding that the bank was continuing to invest in its systems.However, he did not mention that the bank had to remediate "weaknesses" and "issues" concerning transaction monitoring and reporting that were highlighted in the 2017 annual report.The contingent liability indicates that the NAB board believes the company might have a financial exposure to the compliance issues.