Police, in an ongoing investigation, traced the man's IP address and found that he was using a specialised internet child pornography file sharing programme.
A search of his apartment in the Thessaloniki suburb of Kalamaria turned up more than 1,500 files with child pornography material stored on a hard disc drive.
The man was not in the apartment at the time, and is believed to be abroad. A case file was drafted and sent to the local prosecutor.
In the last two days, the Thessaloniki electronic crimes squad arrested a 35-year-old man in Thessaloniki who had more than 30,000 files of hard-core child pornography material in his PC and a 52-year-old seaman on the island of Corfu who had more than 250 files containing photographs and videos of children and adolescents in sexual acts.
The case of the 35-year-old in Thessaloniki is the biggest with respect to the material seized that has been uncovered by authorities in northern Greece involving a single perpetrator.