The suspect, who also worked on occasion as a childminder, was said to have hidden his own criminal record by using a false name and forged documents.

All of the victims were between the ages of four and eight, with the suspect generating “a huge quantity of photos and videos” which he then
distributed on paedophile forums through the encrypted Tor network which links to the dark web.

“He took advantage of his status as a teacher to gain access to the victims and gain the trust of parents, and in that way he was able to generate an enormous amount of material,” Spain’s National Police said in a statement.

The investigation began early last year after police were tipped off by their Australian counterparts who detected material on Tor that appeared to be uploaded by someone in Spain.

Spanish police tried to identify the locations where the pictures and videos were taken, concluding that much of the material appeared to have been gathered at a primary school in Madrid.

Investigators honed in on a teacher who had changed his identity to hide the fact he had a criminal record in Britain and had been sentenced to two years in jail for similar acts involving images of children being sexually abused.

– ‘Urgent operation’ –

Police staged “an extremely urgent operation to ensure his arrest” in June last year.

During the search they discovered material held on 10 different devices, along with forged documents the suspect had used to enter Spain and get a job as a teacher under a false name.

In Spain, anyone working with minors must by law present a certificate proving they have no history of sexual offences — and a falsified copy certificate was found at his house alongside the means to create such a document.

The man has been charged with suspected child sex abuse offences as well as another charge relating to the discovery and disclosure of secrets, relating to the violation of privacy.