The Vatican may try a man who scaled St Peter's Basilica to protest against laws that he says lost him his business in Italy, a spokesman for the papal city state said on Friday.

Marcello di Finizio has been held in the small Vatican jail since being arrested after spending the night of December 21 on a ledge of the church just above the central balcony where the Pope addressed crowds on Christmas Day.

It was the fifth time in recent years that he had climbed the basilica, holding banners that variously criticized politicians, Europe and "financial dictatorship", and calling on Pope Francis for help.

The Vatican's chief prosecutor, Gian Piero Milano, whose official title is "promoter of justice", will request next week that Di Finizio stand trial, spokesman Ciro Benedettini said. A Vatican judge will then decide whether the prosecution should proceed.

Di Finizio, who is 47, according to Italian media, apparently used ropes to lower himself onto a ledge on the church's facade from a roof that is open to tourists.

He says he lost a beach-front concession where he ran a bar called "The Voice of the Moon" because of changes made several years ago to European and Italian laws to make the sector more competitive.