Updated

Philippine police say cracking down on online child pornography is a growing challenge because criminals increasingly use unregistered pre-paid mobile phones lines and Internet devices that are hard to trace.

Gilbert Sosa, head of the anti-cybercrime unit, says that telecommunications companies are also refusing to turn over telephone and Internet log files of suspects following the suspension of the cybercrime law over privacy concerns.

He said Friday that the obstacles are preventing Philippine police from gathering evidence from tens of thousands of sites transmitting child abuse materials.

Unregistered SIM cards can be purchased in neighborhood stores throughout the country with no identification required.

In 2012, British, American, Australian and Filipino investigators dismantled a ring that streamed footage of child sex abuse from the Philippines and have since arrested 29 people.