The money laundering compliance saga at Commonwealth Bank of Australia is poised to induce an unwanted headache for one of the world's largest financial institutions.HSBC, a pillar of Hong Kong's vigorous banking sector for more than 150 years, could be dragged into investigations into how crime syndicates operating in Australia were able to move dirty cash valued in the hundreds of millions through CBA's local and international network.Austrac's statement of claim against CBA alleges that much of the suspicious cash that washed through the bank's retail operations was transferred to bank accounts in Hong Kong.While Austrac has been able to document how dirty money flowed into Hong Kong from CBA accounts in Australia, mystery surrounds where large licks of the loot have gone since.The ability of Australian authorities to track down the cash mostly rests with investigators from the Commercial Crime Bureau of the Hong Kong Police Force.Criminals looking to make their ill-gotten cash more conveyable might have been be tempted to convert their funds into a global currency such as the American dollar.In Hong Kong, Commonwealth Bank relies on HSBC to clear large value money transfers and payments in US dollars.That could mean any investigation of funds shifting out of CBA's Hong Kong branch might require police to examine whether HSBC's banking infrastructure was used to cleanse dirty money.Such a development would be hard to bear for HSBC's senior management and board.In recent years HSBC has invested heavily in its anti-money laundering capabilities following the reputational fallout of past violations of international laws.Between 2012 and 2015 the world's fourth-largest bank copped fines worth more than $US 2.2 billion for failing to comply with anti-money laundering laws around the world.This included a record $US 1.9 billion fine imposed on the bank by US authorities.CBA's travails are also likely to put the regulatory spotlight on the Hong Kong operations of other Australian banks, including Westpac and ANZ, that offer multi-currency deposit accounts to retail customers in China's special administrative region.The anti-money laundering scandal has taken a toll on shareholders, with the stock price sliding more than 11 per cent since details of the Austrac court action broke on 4 August.There was more negative news for investors on Tuesday after Australia's most active litigation funder, IMF Bentham, confirmed that it would fund an open class action against the bank for not disclosing details of its non-compliance problems two years ago.In a filing to the ASX, IMF Bentham said shareholders who bought shares between 17 August 2015 and 3 August 2017 were eligible to join the litigation."The claim will allege breaches by CBA of its continuous disclosure obligations arising from the alleged breaches as well as misleading and deceptive public statements claiming performance by CBA of its obligations under the AML Act," the company told the ASX.Thousands of shareholders who are registered to participate in the bank's dividend reinvestment plan were also dealt some disappointing news.CBA announced that the issue price for shares to be issued to shareholders reinvesting their final dividend for