The Australian Transaction Reports and Analysis Center, better known as AUSTRAC, on Thursday lodged in the Federal Court an additional 100 alleged violations of reporting requirements, bringing the total to more than 53,800. Each is punishable by a fine of up to 21 million Australian dollars ($16 million).
The new allegations also extend the timeframe of the bank's alleged misbehavior from three to six years.
"These allegations are very serious and reflect systemic non-compliance over approximately six years," AUSTRAC chief executive Nicole Rose said in a statement.
The bank said in a statement it would update its statement of defense to the court in due course.
On Wednesday, the bank admitted to the court that it was late in reporting more than 53,500 suspicious transactions exceeding AU$10,000 between 2012 and 2015.
But it blamed a single software error in its deposit-taking automated teller machines and argued those violations should be treated as one rather than as a series of individual offenses.
AUSTRAC launched a civil prosecution against the bank in August over suspicious transactions totalling more than AU$77 million. Within weeks, the bank announced that its chief executive Ian Narev will retire by June 30, 2018.
Last month, the government announced a high-level inquiry into misbehavior in Australia's financial sector.
A royal commission - the highest form of investigation in Australia - will review the banking, pension and financial services industries.
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