Many of these images were taken from platforms such as TikTok and Instagram before spreading on Telegram.
Despite rules against sharing this kind of content, Telegram's features make it easy for groups to pop up again after being shut down.
AI Forensics is now urging the EU to step in with stricter regulations.
Meanwhile, Telegram's co-founder Pavel Durov denies the platform is enabling illegal activity, but critics say current efforts just aren't enough.