'Facebook' is gradually building "shadow profiles" of non-users of the social networking site, a privacy watchdog has claimed.

Ireland's Data Protection Commissioner (IDPC) claims that users are encouraged to give out non-user's personal details, like names, phone numbers and email addresses, which Facebook uses to create "shadow profiles" of those people.

Ciara O'Sullivan, a IDPC spokeswoman told 'FoxNews.com' that its audit of Facebook Ireland's privacy policies was part of a "statutory investigation" that the office anticipates will lead to immediate changes.

"The Office of the Data Protection Commissioner will be commencing a comprehensive audit of Facebook Ireland before the end of the month," O'Sullivan said.

However, Facebook, with 800 million users, has refuted allegations that it is tracking information of non-account holders too. "The allegations are false," Facebook's spokesman Andrew Noyes was quoted as saying.

He added: "We enable you to send emails to your friends, inviting them to join Facebook. We keep the invitee's email address and name to let you know when they join the service.

"This practice is common among almost all services that involve invitations -- from document sharing to event planning. The assertion that Facebook is doing some sort of nefarious profiling is simply wrong."

The social network also said information from users it not used to target advertisements and information is not sold to other people.