In a filing with the Securities Exchange Commission of the US, the company said 8.7 per cent of its 955 million user base -- translating into 83 million -- are not real accounts.
According to Facebook, 4.8 per cent of its wider user base are "duplicate" accounts -- an account that a user maintains in addition to his or her principal account as of June 30, 2012.
In addition to this there are "false" accounts, which in turn can be divided into two categories -- user-misclassified accounts and undesirable accounts.
User-misclassified accounts are those where users have created personal profiles for a business, organisation, or non-human entity such as a pet and undesirable accounts represent user profiles that are intended to be used for purposes that violate our terms of service, such as spamming.
"As of June 30, 2012, we estimate user-misclassified accounts may have represented approximately 2.4 per cent of our worldwide monthly active users (MAUs) and undesirable accounts may have represented approximately 1.5 per cent of our worldwide MAUs," Facebook said.
The social networking giant further noted that the percentage of accounts that are duplicate or false is meaningfully lower in developed markets such as the United States or Australia and higher in developing markets such as Indonesia and Turkey.
As of June 30, 2012, Facebook had 955 million MAUs, an increase of 29 per cent from a year ago period.
Users in Brazil, India, and Indonesia represented key sources of growth in the second quarter of 2012 relative to the prior year.
As of June 30, 2012, Facebook had 54 million MAUs in Brazil, an increase of 146 per cent compared to the same period in 2011; 59 million MAUs in India, an increase of 84 per cent compared to the same period in 2011; and had 55 million MAUs in Indonesia, an increase of 24 per cent compared to the same period in 2011.
Facebook further noted that worldwide daily active users increased 32 per cent to 552 million on average during June 2012 from 417 million during June 2011 and the overall growth was driven largely by increased mobile usage of Facebook.
Growth in daily active users was across major markets including Brazil, the United States, and India.