German authorities have uncovered one of the largest child porn platforms in the darknet with four people arrested in the case, the Federal Criminal Office (BKA) said on Monday in the southwestern city of Wiesbaden.

Three German men are accused of having operated the “Boystown” platform as administrators.

Meanwhile, another German suspect is said to have been one of the most active users of the portal which had more than 400,000 members and to have posted more than 3,500 posts.

German authorities arrested the suspects in mid-April and they have been in custody since.

Prior to the arrests, investigators from the BKA and the Frankfurt Public Prosecutor's Office searched also seven addresses in three German states -- North Rhine-Westphalia, Bavaria and Hamburg.

At the same time, another suspected gang member was arrested in Paraguay following a request by German law enforcement authorities, the BKA said.