Authorities worldwide have completed a huge operation closing down seven child pornography rings.

In 2006, authorities in Queensland, Australia received a tip regarding a sexually explicit video on the Internet. Police followed up on the tip, only to discover a video of a young Dutch victim being sexually molested. Soon after, the Belgian police were contacted and an investigation, nicknamed “Operation Koala,” began.

Belgian authorities tracked down and arrested the assailant, who then provided information on the video’s producer, an Italian pornographic website operator.

Belgian police then contacted Italian authorities, who located the producer, arrested him and shut down his website. Italian police then found 50,000 emails addressed to the website, which they handed over to Europol.

Europol sent the emails to authorities in the emails’ 28 countries of origin.

More than 11,000 of the emails originated from the United States.

Of those 11,000, 700 emails became leads, investigated by the Federal Bureau of Investigation, United States Postal Inspection Service and Immigration and Customs Enforcement. The Department of Justice’s Child Exploitation and Obscenity Section also played a crucial role, along with local and state law agencies.

Several child predators have located and arrested in the United States, including:

A New Jersey father who pleaded guilty to taking sexually explicit images of his nine-year-old daughter, was sentenced to 20 years in prison. Authorities also found approximately 130,000 sexually explicit images of minors upon searching the man’s home.

A fifth-grade teacher in Arizona, a customer on the Italian porn site, was charged with sexual exploitation of children, after a search of his home led to allegations he instigated sexual contact with his female students.

A convicted Philadelphia sex offender who had previously spent 15 years in prison was charged with distributing, advertising and receiving child pornography. Authorities say evidence indicated that he ran two global online child pornography bulletin boards.

The one tip, received three years ago by Australian authorities, has led to the unraveling of seven incomprehensibly large international porn rings on three continents.

Authorities in the United States, have so far conducted 250 investigations resulting in 60 arrests. Several at-risk children have been rescued as a result of the operation.

“We’re still working our way through all the cases,” said an FBI agent in charge of the investigation. “Cooperation is the key. During our regular meetings with postal inspectors, ICE, and DOJ, we do whatever needs to be done as a team to make sure the cases keep moving forward.”

Sachin Seth is the Blast Magazine world news reporter. He writes the Terra blog. You can follow him on Twitter at twitter.com/sachinseth