It is unclear when the photograph — which shows Garibotto’s skimpily clad buttocks — was first liked, but the interaction was visible on November 13, before being unliked the next day, after CNA approached the Holy See Press Office for comment, the news agency said.
Now, the Vatican said it is trying to get to the bottom of the incident.
“We are in touch with Instagram to find out what happened,” Vatican spokesman Matteo Bruni told CNN on Friday.
CNN has reached out to Facebook, which owns Instagram, for comment.
Some 7.4 million people follow the pontiff on his official Instagram account, but the account does not follow anyone back. There is no evidence that the Pope liked the image himself.