If you're told to do something that you feel is illegal, what would you do?

What they are really asking

This one has a right answer, and the interviewer knows you know it. So the real test is how you'd do it. Can you say no to someone senior without panic or drama? Do you know that most companies have a process for this, like a compliance team, HR or an ethics line? And do you check the facts before accusing anyone?

The weak answers are at the extremes. "I'd do what I was told" is an instant fail. "I'd call the police immediately" skips steps and suggests you'd make a crisis out of a misunderstanding. The strong answer is calm and firm: clarify, raise it, refuse, escalate, and keep a record.

A shape that works

Clarify, say it plainly, refuse, escalate. First, make sure you've understood; sometimes an instruction sounds wrong because it's missing context. If it's still wrong, say so directly to the person and explain your concern. Decline to do it. If they insist, take it to the right channel, such as compliance, HR or a manager above them, and write down what happened. Say this in a steady voice. The calm is part of the answer.