Officials from the Data Protection Commissioner’s office will visit Facebook’s Dublin headquarters today in a follow-up to a major audit of the company’s privacy policies and use of customer data.

The social networking company agreed to make significant changes to its privacy policy, and to make changes to how retains and deletes user data, following the publication of the audit last December.

In that report, the commissioner said that indefinite retention of users’ ‘ad click’ data by Facebook was “completely unacceptable”.

Facebook agreed the data, relating to adverts users clicked on, will now be deleted within two years.

The report also recommended changes to privacy policy surrounding third-party applications used by Facebook customers.

However, the commissioner found no evidence to suggest the company had built up so-called shadow profiles, the alleged practice of collection of data on non-members.

The audit criticised Facebook for the way it implemented its facial-recognition feature. In response Facebook said it would alert users in January that they could opt out of facial recognition.

The site also committed to make progress by the middle of this year on deletion of information such as friend requests, “pokes” and photo “tags”, over which users previously had limited control.

As Facebook’s European headquarters is located in Dublin, the commissioner has jurisdiction over its users outside the US and Canada, meaning the audit has implications for about 700 million users worldwide. The company claimed 901 million active users at the end of March, with some 80 per cent of those based outside the US and Canada.

Deputy data protection commissioner Gary Davis, who headed the audit last year, will spend the rest of this week on the full re-audit at Facebook’s offices.

The commissioner has said his audit of Facebook was “the most comprehensive and detailed” ever undertaken by his office and that it placed “a significant burden” on resources for the three months of its duration last year.

A Facebook spokesman said that over the past six months it had been keeping the commissioner’s office “closely informed” of its progress in implementing the recommendations outlined in the December audit report.

He noted the commissioner planned to publish a report of his findings from this week’s on-site audit meeting in due course.

“We look forward to the meeting and will continue to work cooperatively with our regulator in Ireland.”