This report from Canada’s Globe and Mail recounts how the alleged relationship between Eliot Spitzer (the former governor of New York who resigned in disgrace
last month) and a high-priced call girl was uncovered by Mr. Spitzer’s bank.

It reported "abnormal activity. … what tweaked
the software in Mr. Spitzer’s case was not money moving from point A to
point B. In fact it was the former governor’s efforts in trying to
conceal the transactions that triggered the alert…In Mr. Spitzer’s case, three cash transactions amounting to more than
$10,000 within a relatively short time frame set off alarms.."

In Australia, "if (Austrac) analysts determine that a
Suspect Transaction Report (SUSTR) may be of interest to one of AUSTRAC’s partner agencies,
the report may be referred to the agency for further enquiries. In
addition, suspect reports are made available (with appropriate
restrictions) to partner agency users via the AUSTRAC TES system."