Authorities in Germany managed to take down one of the world's biggest child sex abuse platforms following a large-scale investigation which led to several arrests in mid-April, a police statement confirmed on Monday.

The platform "Boystown" was active since at least June 2019 and had a membership of over 400,000. It was only accessible via the so-called darknet.

Four German citizens between the ages of 40 and 64 were detained in relation to the case, three on suspicion of working as administrators for the platform — one of whom was arrested in Paraguay. Another man was taken in under suspicion of being a registered member and the platform's most active user, having contributed more than 3,500 posts.

What did the police discover about the site?

The investigation spanned months and was led by a German task force working in coordination with Europol, as well as authorities from the Netherlands, Sweden, Australia, the United States and Canada.

The platform provided a space for users to share recordings of abuse of minors including "of the most serious sexual abuse of young children," the statement from the Germany's federal investigative police force (the BKA) said.

The platform included several communication channels for users. The members also received advice from platform administrators for how to access the site in the most secure way and how best to avoid detection and subsequent criminal charges.

What happened to the men who were arrested?

The accused were arrested after police searched their homes. The three men in Germany were arrested and taken to Frankfurt am Main on April 14 and 15 for questioning. The fourth man, who was one of the three site administrators and was arrested in Paraguay, is expected to be extradited to Germany.

The raids were carried out across Germany. Another of the administrators, a 40-year-old man, was arrested in the town of Paderborn in the western state of North Rhine-Westphalia, while the third administrator, 49, was arrested near the southern city of Munich.

The fourth man, 64, who was suspected of being the site's most prolific user, was detained in Hamburg.

Police were able to close down "Boystown" and several other chat platforms following the raids.

Difficult to track down the platform's users

Asked about the significance of the arrests, Janina Semenova from DW's digital desk, called them "a major sensation for German investigators," noting that with 400,000 members around the globe, Boystown was "one of the biggest dark web platforms of this kind."

Semenova also spoke about the anonymous nature of the darknet, saying, "of course this anonymity makes it really hard to investigate these platforms."

Although authorities were able to infiltrate the site and track down its administrators she says it is unclear if investigators will truly be able to locate many of the platform's users.

Semenova added that when a platform has been taken down in the past users simply formed a new one, but said "in the future, there hopefully won't be any other platforms of this kind."