COPENHAGEN (Reuters) - The identity numbers of around 900,000 Danes, widely used as a means of identification in telephone transactions with banks or medical services, were mistakenly made available on the internet for almost an hour on Wednesday, the Danish government said.
The numbers were mistakenly included by an outside contractor in a database of people who have asked not to receive marketing mail or calls that is made available to Danish firms, according to the daily Borsen.
It is common for Danish financial institutions, hospitals and government agencies to ask for the civil registration number as a proof of identity in telephone inquiries, raising the possibility of widespread abuse.
The government said the list had been downloaded 18 times in the 51 minutes that it was accessible.
"It's simply a mistake that should not happen ... I will consider the implications of this very thoroughly," Economic Affairs and Interior Minister Margrethe Vestager said in a statement on Thursday.
The leak was discovered by Finn Gilling, owner of a company that works with private data.
"We reacted immediately and notified the Central Office of Civil Registration," Gilling told Borsen.
(Reporting by Ole Mikkelsen; Editing by Kevin Liffey)