The probe will determine if Fry committed a crime under the Defamation Act when he appeared on RTE in 2015.
According to Irish Independent, a member of the public contacted police after the comedian spoke about God during an interview with Irish TV presenter Gay Byrne.
The person, who wished to remain anonymous, told the news outlet it was their "civic duty" to report the comments which he alleges were in breach of the Defamation Act.
During the interview, when Byrne asked Fry what he would say if he was confronted by God, he replied: "How dare you create a world in which there is such misery that is not our fault? It's not right.
"It's utterly, utterly evil.
"Why should I respect a capricious, mean-minded, stupid God who creates a world which is so full of injustice and pain?"
Questioned on how he would react if he was locked outside the pearly gates, he responded: "I would say, 'Bone cancer in children? What's that about?'
"Because the God who created this universe, if it was created by God, is quite clearly a maniac, utter maniac.
"Totally selfish. We have to spend our life on our knees thanking him? What kind of God would do that?"
Fry later said he was not "offensive towards any particular religion".
The Defamation Act prohibits people from publishing or uttering "matter that is grossly abusive or insulting in relation to matters held sacred by any religion, thereby causing outrage among a substantial number of the adherents of that religion".
If convicted of blasphemy, Fry could face a £22,000 fine.