What is clear is that a like from the pope's verified Instagram account @fransiscus ended up on a picture published by the Brazilian model Natalia Garibotto.
It is unclear when the like marking appeared, but it appeared as late as November 13 before it disappeared again.
"Will end up in heaven"
Garibotto, who has 2.4 million followers and whose account mainly consists of more or less undressed photos, is said to have taken the attention calmly and joked that she "will at least end up in heaven", reports The Guardian.
Garibotto's management company has also taken advantage of the situation and wrote last week on social media that it has now "received the pope's official blessing".
Sources close to the pope's press department tell the Catholic news agency CNA that an investigation has been launched to find out how it came about that the photo was liked.
Pope Francis is relatively popular on social media with 7.4 million followers on Instagram and 18.8 million followers on Twitter.
However, he does not usually create content on the channels himself, but surrounds himself with a group of employees who handle the social media, according to Robert Mickens, editor of the Catholic daily La Croix.
- He approves of tweets, but not likes, and on occasion he wants to write something on Twitter due to an ongoing situation.
He could not have had anything to do with this.
It's the communications department, and how it went to who knows, Robert Mickens tells The Guardian.