The men were arrested in Sweden, Canada, the Czech Republic, Germany, Norway, Poland and Switzerland, Europol writes in a press release.
All suspects arrested are men aged 22 to 54.
Investigators suspect that the men paid with cryptocurrency to gain access to forums on the darknet, where they could download or view videos of children being abused.
More than 460 items, including electronic devices, crypto wallets, drugs and large amounts of doping agents, have been seized.
The investigation, led by Norwegian police, is continuing and further arrests are expected, according to Europol.
