Many have wondered how Wells Fargo employees were able to open millions of fake accounts without getting caught.
Modern banks are supposed to have inspections and risk exams to catch this kind of fraud.
Now it has emerged that Wells Fargo's internal inspections of local bank branches come with a friendly 24-hour heads up to managers and employees.
That tip-off, first reported by The Wall Street Journal, likely gave employees time to hide evidence that would have alerted internal investigators to the opening of fake accounts.
For instance, more than a dozen Wells Fargo employees told the Journal they witnessed documents being forged and papers getting shredded to cover up this activity.
Regulators have said that as many as 2 million bank and credit card accounts were opened by Wells Fargo without authorization, at times by using phony email addresses and PIN numbers.
Related: Wells Fargo admits to signs of worker retaliation
Wells Fargo (WFC) confirmed to CNNMoney on Wednesday the existence of a 24-hour advance notice, explaining it's given "so the branch can ensure it is staffed to assist with the review and maintain customer experience."
Wells Fargo has now decided to eliminate the 24-hour warning about inspections.
But even that shift is coming with a time lag. Wells Fargo said it won't be fully implemented until the end of March.
A spokeswoman declined to say whether the move was triggered by media attention.
Wells Fargo noted that much of its documentation has become electronic, including electronically-captured signatures. The bank said that for years it has reviewed digital copies of new account forms and signature cards in advance of branch visits and without prior notice.
For the in-branch reviews, Wells Fargo said only internal branch logs that are not currently captured electronically are looked at. That includes logs for cash shipment and notary activity.
Related: Wells Fargo is closing over 400 bank branches
The fake account scandal has thrust Wells Fargo into turmoil since it broke in September. The $185 million in fines were nothing in comparison with two Congressional hearings, where the bank's CEO was raked through the coals.
It also led to multiple investigations from state and federal agencies, which are still ongoing. Longtime CEO John Stumpf abruptly retired after his Congressional hearings and the bank's once-vaunted reputation has been tarnished.
Wells Fargo has responded by ending the wildly unrealistic sales goals that employees said led to the illegal activity.
The bank's new compensation structure, rolled out earlier this month, puts more emphasis on customer service and features stronger oversight "to monitor behavior," including at the local level.
For instance, Wells Fargo has launched a mystery shopper program at branches that by definition doesn't give employees any advance notice.
"People in the branch don't even know that any review is going on," the Wells Fargo spokeswoman said.
Wells Fargo aims to conduct about 4,000 mystery shops per quarter this year.
During the scandal, Wells Fargo also started conducting conduct risk exams at branches. Wells Fargo said these reviews are unannounced and the branches are selected for exams based on risk indicators.
