Facebook has confirmed that it is in the throes of fixing a software bug that wipes the email addresses of contacts stored on users' devices.
The bug replaces the email addresses stored on people's mobile phones with @facebook.com ones, which the site started rolling out to existing site users recently.
In a statement to IT Pro, the company said the problem was caused by an application programming interface (API) error.
"Contact synchronization on devices is performed through an API. For most devices, we've verified that the API is working correctly and pulling the primary email address associated with the users' Facebook account," said the statement.
"However, for people on certain devices, a bug meant devices [were] pulling in the last email address added to the account, rather than the primary email address, resulting in @facebook.com addresses [appearing].
"We are in the process of fixing this issue and it will be resolved soon," it concluded.
According to a report on the BBC Technology site, affected users tend to have activated Facebook Contact Sync on Blackberry and Android phones. Devices equipped with beta versions of Apple's iOS6 and Microsoft's Window Phone 8 are also understood to have been affected.
