An Italian priest is under investigation for conducting Mass in swim trunks and using an inflatable mattress as an altar

• An Italian priest is being investigated for holding Sunday Mass at the beach in his trunks.
• Father Mattia Bernasconi was seen conducting the service with a floating mattress as an altar.

Italian authorities are investigating a priest who celebrated Mass on the beach with an inflatable air mattress as an altar.

Father Mattia Bernasconi, from the San Luigi Gonzaga parish in Milan, had been helping with a week-long camp for high school students organized by Libera, an anti-mafia organization, according to local media reports.

They visited a beach near Crotone on Sunday, where Bernasconi had planned to conduct Mass among some nearby pine trees, per the Italian newspaper Corriere della Sera.

However, they couldn't find a proper spot in the forest, and were desperate to get some shade, Bernasconi said, per the outlet.

"It was very hot," he said, according to Corriere della Sera. "So we said to ourselves: Why not in the water?"

"A family heard us and gave us their mattress, which we transformed into an altar. It was beautiful, even if we got sunburnt," he added, per the outlet.

Photos soon emerged online of Bernasconi holding Mass in his swim trunks, with his arms outstretched over a floating air mattress in the sea. The act has prompted warnings from Catholic authorities and an investigation from the Crotone Prosecutor's Office.

A video of the incident shows a group of teenagers in swimsuits kneeling, squatting, or sitting in front of Bernasconi as they participated in the impromptu service.

Responding to the incident, the Archdiocese of Crotone-Santa Severina released a statement saying it was "necessary to maintain the minimum decorum and care for the symbols necessitated by the very nature of liturgical celebrations."

"In some special cases, during retreats, school camps, in vacation spots, it is also possible to celebrate Mass outside of a church," the statement read. " However, it is always necessary to contact the ecclesial leaders of the place where you are, to advise on the most appropriate way of carrying out a Eucharistic celebration of this kind."

According to the Italian newspaper Il Giorno, Crotone's chief prosecutor Giuseppe Capoccia said his office had launched an investigation into an "offense to a religious confession."

Bernasconi apologized for his actions in an interview with Corriere della Sella. "It was absolutely not my intention to trivialize the Eucharist or use it for other messages of any kind," he said.

He added that he believed the service was appropriate and respectful enough given the "simplicity and the poverty of the means."

When approached by Il Giorno, Bernasconi declined to comment further and said he wouldn't stand in the way of Capoccia's investigation.