By Anne Fisher, contributor
FORTUNE — Dear Annie: I recently fled my comfortable and well-paid job as an auditor with an accounting firm because I couldn’t ignore the unethical practices that were commonplace there. The partners turned a blind eye when presented with “creative” accounting and window dressing by clients. Even fictitious transactions and questionable payments were approved with a wink and a nod.
I believe the banking crisis of 2007 and 2008 would not have had such catastrophic effects if external auditors had done their job properly, so I was losing sleep over being made an unwilling party to these shady dealings. But the question is, when job interviewers ask why I quit, what should I tell them? — Mr. Clean
Dear Mr. Clean: Yikes. Just in case you harbor any second thoughts about the wisdom of giving up a “comfortable and well-paid” job in this rocky economy, rest assured that you did the right thing. “I’ve interviewed job candidates who had quit their previous positions because of ethical concerns, and it later all came out in the news,” says Janice Ellig, co-CEO of Manhattan-based executive search firm Chadick Ellig.
“Unethical behavior will come to light eventually,” she adds. “And, as we saw with scandals like Enron and WorldCom, the auditors get sued, fined, and tarnished along with the perpetrators, so you’re absolutely right to protect yourself by getting out now.”
John Challenger, CEO of outplacement giant Challenger Gray & Christmas, agrees: “You are to be applauded for taking an ethical stand. It takes real courage to leave a job when you don’t have another one lined up.”
But, for now at least, virtue has to be its own reward, since telling job interviewers about your former employer’s misdeeds would be unwise.
“The trouble is that anyone who wasn’t there and didn’t see what you saw will have no way of knowing whether your accusations are true, or whether you’re just a troublemaker,” Challenger says. “Prospective employers will worry that you might make them look bad someday, too.”
Luckily, there are plenty of truthful ways to talk about why you left without opening that can of worms — and without falling back on the old standby about hankering after a bigger challenge, which interviewers hear so often that it tends to make their eyes glaze over (even if it’s true).
“Look for other things going on at the company that could reasonably have contributed to your decision to leave,” Challenger suggests. “For example, maybe the firm has been struggling or restructuring and there has been a wave of departures, or the company changed its scope of work or its strategy in some way. Every situation is different, of course, but if you think about it carefully, you can almost always find something that doesn’t put either you or the company in a bad light.”
Janice Ellig points out that, if you truly want to prevent another Enron, “there are regulators you can contact to report misconduct. There’s nothing wrong with being a whistleblower — but not in a job interview.”
Instead, she recommends saying something like, “We had philosophical differences on how the business should be managed, and it seemed best if we parted ways.”
Don’t worry if that seems a little vague. “If an interviewer presses for more details, you can reply, ‘Sorry, but I’d be revealing proprietary information,’” Ellig adds.
It may help to consider two good reasons why you needn’t get too hung up on formulating an answer to the why-did-you-leave-your-last-job question. The first one is that any interviewer worth his or her salt is far more interested in what you can do in the future than in rehashing your employment history, so concentrate on steering the conversation toward what you can bring to an employer right now.
And second, you’re hardly alone in wanting to change jobs. The Bureau of Labor Statistics reports that almost 2 million workers quit voluntarily in May (the latest month for which figures are available). That’s the highest monthly figure since November 2008.
What’s more, a new study by PriceWaterhouse Coopers says that turnover among “high performers” is increasing. The percentage who flew the coop in 2010, at 4.3%, is approaching 2007 (pre-recession) levels, and PwC’s researchers expect that to double, to 8.7%, by 2013. Against that backdrop, you may not need to do as much explaining as you think you will.
Bear in mind, too, that any job interview is a two-way street. “You’re evaluating the employer too. Don’t take any job unless and until you’re convinced the company’s ethical standards are high,” advises Challenger. “In an interview, don’t grill them about it, but keep your eyes and ears open and trust your gut.”
Talkback: Have you ever been confronted with unethical behavior by colleagues or higher-ups? What did you do about it? Leave a comment below.
