Can a bank ask where you got money?

Could you elaborate on whether a bank has the right to inquire about the source of funds deposited into an account? Are there any regulations or policies in place that govern such inquiries? Additionally, what are the potential consequences if an individual fails to disclose the origin of their funds upon request by a bank? Furthermore, are there any specific scenarios where a bank is more likely to ask about the source of funds, and what steps can one take to prepare for such inquiries?