A global sting on people distributing images of children being sexually abused via social networking sites like Facebook, sparked by New Zealand's Department of Internal Affairs, has snared 55 offenders.

Operation Laminar, which spanned 20 countries, also saw 12 abused children, including one from New Zealand, removed from harm.

The NZ Department of Internal Affairs' censorship compliance unit in October 2010 found significant numbers of images showing children being sexually abused and exploited being exchanged through groups on social networking sites like Facebook.

International law enforcement agencies were alerted and the Department of Internal Affairs provided evidence to the countries involved in the operation.

It also worked with Interpol and Facebook officials.

Department spokesman Maarten Quivooy says the 55 people identified in the investigation are regarded as the "top offenders" in the trade of objectionable images.

Most of the 55 are in prison or are facing prosecution and some were also involved in the sexual abuse of the children in the images. None were from New Zealand.

Five New Zealanders, who played lesser roles in the groups, were uncovered in the investigation that led to Operation Laminar. They are all facing court action.

The countries involved in the operation were Australia, Bosnia, Brazil, Chile, Costa Rica, England, Finland, France, Germany, Indonesia, Italy, Mexico, Norway, Saudi Arabia, South Africa, The Netherlands, Tunisia, Turkey, United States and Venezuela.