The alleged ousting of a bad spirit was carried out in the Roman Catholic Church of the Assumption of the Virgin Mary in the Czech town of Vranov nad Dyji.
And church officials have now 'confirmed' the footage is genuine.
Daniel Trochta, 26, sneaked up to the door after hearing the screaming of an unknown woman.
He then filmed the secret process through a keyhole of the church.
He captured people standing close to the church’s altar and the very loud screaming and crying woman - including vulgar words shouted in Czech.
The video, posted on YouTube by Trochta in February, was largely ignored until the church confirmed it was genuine last week.
The author wrote: "I filmed it through a keyhole. I suggest that you use headphones while watching it."
Catholic Church priest Marek Dunda confirmed that the exorcism was genuine but declined to comment further.
"If something is filmed through a keyhole, there is nothing more to say about it.
"We were asking God to protect and to liberate the person. We used a Latin prayer asking for a help."
Read Full Story: Mirror UK