BERLIN — A leading German privacy official on Wednesday accused Facebook of using face recognition software in a manner that violates German and European law.

Johannes Caspar, a data protection expert with the city of Hamburg, called on the US-based social networking company to delete from its site the individual biometric data it has collected.

"If the users' data falls into the wrong hands, it would be possible to compare and identify anybody captured in a photo taken with a mobile phone," Caspar told the Hamburger Abenblatt newspaper.

The programme allows Facebook users to locate new "Friends" after discovering their identity through a biometric data scan.

The programme tries to match data captured in a picture with the trove of data it has already collected from its hundreds of millions of users.

"This is what's most problematic. The programme feeds off a stock of data designed to physically identify millions of users," he said.

He further scolded Facebook for collecting and storing biometric data without users' consent, insisting the practice violates privacy laws.

Germany, which is considered a leader on Internet privacy issues, has criticised Google for its "Street View" programme, which makes street-level images freely available online.

German officials also previously urged Facebook to beef up its privacy protections, notably over its Friend Finder feature, which allowed the site to register or even import users' entire email address books without notifying them.

In January, Facebook agreed to inform its members that it had obtained email addresses in their accounts.

Facebook claims to have more than 750 million members.