if you're on a tourist visa, you will most likely be asked to close the account and take all the money out and will not be allowed to open an account anymore until you get a long term visa. If you own a property here, bring the title deed with you and you should also be able to keep the account.
Banks won't steal your money unless they think it's a mule account. If you come back and you can verify you are the owner with your passport etc then you'll get your money back. They just want to verify and also scan facial recognition.