As initially reported in the Upper Austrian News online site, and confirmed by the state prosecutor's office spokesman Philip Christl, the man was placed into detention in December, after US-based social network Facebook detected the child pornography, and informed the FBI.
Some of the abuse is believed to have occurred in the man's home country of Romania, where he is also believed to have abused a seven-year-old child.
According to the report, the man sought his victims among the children of the homeless and prostitutes.
In addition to the abuse in Romania, the man is suspected of producing child porn in his apartment in Austria with a girl of kindergarten age. The relationship between the child victim and the man was not disclosed.
Police report that the investigation is ongoing, and the man will be remanded in custody until his trial. He is believed to have made a full confession.
"The investigation is pointing towards aggravated sexual abuse of minors and [production of] pornographic images of minors. Our investigation is not yet complete" said Christl.