Instagram has been fined by an Irish regulator after an investigation found the social media platform mishandled teens' personal data.

The Irish Data Protection Commission told the Post that it had made a final decision last week to fine the company 405 million euros.

The fine is the second-heaviest fine imposed under the European Union's strict privacy rules, after Luxembourg regulators fined Amazon 746 million euros last year.

Instagram parent company Meta, which also owns Facebook, may appeal the decision.

The Irish watchdog's investigation focused on how Instagram disclosed personal data of users between the ages of 13 and 17, including email addresses and phone numbers. The minimum age for Instagram users is 13 years old.

Under EU data privacy rules, the Irish regulator is the lead regulator for many US technology companies with European headquarters in Dublin.

Last year, he fined WhatsApp 225 million euros for violating transparency rules regarding data sharing with other Meta platforms.