From the Treasury finding:

"Banco Delta Asia has been a willing pawn for the North Korean government to engage in corrupt financial activities through Macau, a region that needs significant improvement in its money laundering controls, said Stuart Levey, the Treasury's Under Secretary for Terrorism and Financial Intelligence (TFI). "By invoking our USA PATRIOT Act authorities, we are working to protect U.S. financial institutions while warning the global community of the illicit financial threat posed by Banco Delta Asia."

In conjunction with this finding, Treasury's Financial Crimes Enforcement Network (FinCEN) issued a proposed rule that, if adopted as final, will prohibit U.S. financial institutions from directly or indirectly establishing, maintaining, administering or managing any correspondent account in the United States for or on behalf of Banco Delta Asia.

Such a finding, replete with specific allegations, is very unusual, to the point where it would be very surprising if there is not substantial evidence to back it up.

Note for the record that Bank Chairman and controlling shareholder Stanley Au has called the allegations a "ridiculous joke."

Regardless of the truth of the allegations, the government of the Macau SAR is taking the situation very seriously, knowing that a bank run could lead to the collapse of the bank or even undermine the entire financial system. On Saturday, the Macau Chief Executive appointed two administrators to oversee the bank and "participate in [its] administration," but pleaded with the public not to put credence in allegations, but to wait for authoritative findings.

Remember also that outstanding investigations of Seng Heng Bank and Bank of China's Macau operations on the same grounds are also proceeding - if similar charges are levied against these institutions the fallout would be much more serious.

Has Macau been lax in enforcing anti-money-laundering ordinances and controls?

While the Monetary Authority is generally considered a respectable bank regulator, note that the IMF's last review of financial systems regulation and supervision in Macau found the AMCM "materially non-compliant" in enforcing anti-money-laundering principles.