Authorities held Bishoy Kamel, 32, for four days for managing a Facebook page where people shared cartoons thought to defame the Prophet Muhammed and the religion of Islam.
Pictorial depictions of the Prophet are considered a form of idolatry, and is thus taboo to most Muslims.
Kamel said that while he did indeed manage the Facebook page where the cartoons were found, he didn't control what others posted there. He added that the page was "hacked" on Saturday.
Mohamed Safwat, the man who reported Kamel, claimed that Kamel also "insulted members of his own family" on Facebook.
Earlier this year, Egyptian police arrested a 17-year-old boy for a similar offense. Gamal Abdou Massou was convicted after posting cartoons of the Prophet Muhammad to Facebook, where his friends then shared them out. In April, a judge sentenced Massou to three years in prison.
Like Massou, Kamel is reportedly Christian. Kamel faces up to five years in prison if convicted of blasphemy charges.