A silhouette image of what many believers say looked like that of the Virgin Mary appeared on a portion of glass at a Catholic church days before Christmas in the U.S. state of Georgia, drawing crowds of curious onlookers, CBS News reported.

The "Virgin Mary image" appeared on the window of the Transfiguration Catholic Church in Marietta, Georgia, a "divine phenomenon" that believers are calling a "Christmas miracle."

However, the sceptics say it was simply "faulty coating" on the window pane that reacted to elements outside, leading to the appearance of the foggy figure.

The parish priest of the church, Father Fernando Molina-Restrepo, posted a photograph of the window image on his Facebook page. He said the image appeared on Dec. 12, which marked the Feast of Our Lady of Guadalupe. He said the image can be seen on most sunny days.

The priest wrote: "We may never agree on why or how this image appeared on the window. The true gift to us will be in how we are inspired to be MORE: more forgiving, more accepting, more loving to those with whom we share our lives."

Speaking to CBS Atlanta, Molina-Restrepo denied claims by critics that it was a hoax and that he was the one who drew the image. "There are a lot of people that may think it's a stain or condensation. They ask if I drew it. No, no, no. There's no way you can do that," he said.

Parishioner Victor Jose Alvarado also posted a picture of the image on his Facebook page, according to the Daily Mail.

He wrote: "We started praying and singing songs to the Virgin Mary of Guadalupe, and immediately started feeling peace and the smell of roses!!! We just finished having lunch when someone noticed a very bright sun ray and in front of our eyes her image starting to appear in the window."

One woman who was among a large group of people queuing up to see the "miracle" could not help but cry as she prayed before the image.

"Believe, believe and have faith," she said.