The man, whose identity was not disclosed, was subjected to the punishment in a public square in the city of Kermanshah, northwestern Iran.
Five other Muslim men were also given 70 lashes each for not fasting during Ramadan.
The National Council of Resistance of Iran (NCRI), a political coalition of Iranian democratic organisations, have urged the international community to speak against what it branded “medieval punishments”.
“The silence of the world community, especially of western countries, vis-à-vis these medieval punishments under the excuse of having nuclear talks with Iran has intensified the brutal and systematic violation of human rights in Iran,” it said.
“This will ultimately embolden the Iranian regime to continue its nuclear projects more than before.”
According to a 2014 UN report, the 250,000-strong Christian community in Iran are subjected to persecutions and unfair incarcerations by the government.
The report said a total of 307 people – 49 of whom were Christians – from religious minorities were in prison in Iran as at January 2014
Last year, 42 Christians were arrested. Of these, 35 were sentenced to up to ten years in jail for taking in part in “Christian activities”.
The Iranian government slammed the report, with Mohammed Javad Larajani, head of Iran’s High Council for Human Rights, calling it “a vicious circle, which changes according to the political situation.”