German investigators have been given permission to use computer-generated child sex abuse images as they attempt to catch paedophiles.
Police will be allowed to use the virtual imagery as they attempt to gain access to internet communities they suspect of distributing child abuse materials, after a vote in the German parliament.
The investigation technique has been used in the past but has received some criticism from academics who argue it could pose legal and ethical issues.
Such virtually created images have been distributed both by investigators – a Dutch operation used a computer generated image called "Sweetie" to catch a number of paedophiles – as well as by those genuinely looking for such images.
The justice ministry said that investigators would need a court's approval to use the technique and would only be allowed to use it if there was little or no prospect of investigating by other means.
Justice minister Christine Lambrecht said sites used by paedophiles increasingly demanded that prospective users upload pictures and videos themselves to gain access. She wanted to give investigators all the legal tools possible to track down the people behind the sites, she said.
"It is clear to me that police officials must not use real recordings," she added.
The bill approved on Friday also tightens laws against so-called "cybergrooming". Contacting children for sexual purposes can be punished in Germany with a sentence of up to five years in prison.
However, that was not the case so far if an offender believed he was contacting a child but in fact was in touch with an adult, such as a parent or a police officer. Such attempts also will be criminalized now.