Denmark's national registry was hacked in an incident the authorities described as "extremely serious."

Hackers secured access to personal information on millions of people, the country's digital affairs ministry said on Monday. The compromised information included names, addresses and social security numbers, known in Denmark as national registry numbers.

The data of some 8.8 million registered people was compromised. This figure exceeds Denmark's population size because it includes people who have already died or emigrated, the Danish authorities said in a statement.

The breach by the hackers was through the legitimate login credentials of a local company, initial findings suggest. The hackers have not yet been identified. The means they used to gain access has since been cut off.

The ministry said it was first alerted to an "anomaly" in the system "during September."

Information of deceased, emigrated people included

Denmark has a population of roughly six million people. However, its national registry includes information of eleven million people, which includes the data of those deceased or people who have moved abroad and don't live in Denmark anymore.

Christina Egelund, Denmark's digital affairs minister, said the incident's full extent will investigated by the authorities.

"This is an extremely serious incident," Egelund said. "We are in the process of tracking the exact extent of this incident with all those affected."

Danish news agency Ritzau reported that the register includes information on church membership, details of legal incapacitation and restrictions on legal capacity.

Edited by: Wesley Dockery

Don't let the algorithm hide the news. If you rely on our team for trusted reporting, please take a moment to select us as your Preferred Source on Google, so you'll always see our verified news first.