In neighbouring Loano, Fr Silvano de Matteis earned himself a formal police complaint when he became overly flirtatious with the wife of the local port captain, while another priest was kicked off a cruise ship for molesting its passengers.

Don Juan Pablo Esquivel outraged his parishioners when it emerged that he was living with a gay friend and spent more time body building than he did preparing for his sermons.

And the congregation of another coastal parish was somewhat shocked to discover that beneath his robes, their priest – who has not been named publicly – bore a tribal tattoo across his entire torso and upper arms, a photograph of which appeared in the local Sicolo XIX newspaper when he posed alongside the tattoo artist to display his artwork. Some of the antics of the "playboy priests" – as they have become known in this small, picturesque diocese – are welcomed as a source of tittle-tattle in the pretty cobbled squares of towns across the region.

"For a long time we had a photo of our priest dressed up on the wall in the local bar. He was dressed as a woman, with long blonde wig, stuffed bra and a short dress, and he was pole-dancing. It was very funny," said Daniela Cassani, a local resident.

She was referring to Fr Cesare Donati, the 50-year-old former priest of Bastia who donned the feminine attire during festivities at carnival several years ago. But he was moved on from the town after churchgoers became angry when it emerged that he was running a bar with his live-in girlfriend in a neighbouring town during the week, while still taking to the pulpit at weekends for Sunday mass.

"People got angry, it's hypocritical," she said.

Several years on and Fr Cesare is installed as parish priest in the neighbouring parish of Cenesi, where his behaviour is still raising eyebrows.

"People say he still has the girlfriend but he chooses not to be resident in the village and if that's his only sin perhaps we are getting off lightly," said a shopkeeper in the town, who asked not to be named.

Some of the priests have been accused of much more serious crimes.

Among the worst offenders is Fr Luciano Massaferro, who was sentenced to seven years and eight months for sexually abusing a 12-year-old altar girl. After serving his time, however, he was welcomed back into the Church and is still a priest charged with working with the needy in the parish of Imperia.

Another priest was implicated in running a child prostitution ring. The accusation was not investigated by the Church authorities. Instead, when parishioners' complaints became too vociferous, he was moved to another church within the diocese.

"That priest, who I personally know was involved in paedophilia and made money from it, is now the priest at a church next to a primary school," said one insider. "It is one thing to offer forgiveness to those who repent, but to actively cover up such a scandal and continue to put the vulnerable at risk is another matter."

God moves in mysterious ways. But even so, it seems strange that this state of affairs, which burst across the Italian media last week, was allowed to go on for so long.

Filippo Bardini, the priest in charge of Caritas, the Roman Catholic charity, in the diocese, is one of the few within the Church who will speak openly about the scandal. "It sickens me," he told The Sunday Telegraph. "The Bishop has consistently denied everything and rather than deal with complaints, which have been numerous, he has ignored misbehaviour, covered it up, and even defended and promoted those who should have been unfrocked."

He goes on to list a litany of wrongdoings by parish priests and claims that in the 24 years since Monseigneur Oliveri was made bishop there have been more than 100,000 individual complaints.

"More than half of the 175 priests in this diocese are bad apples and some are even involved in criminal activity, but under Bishop Oliveri they are all brought into the fold and protected. We have to ask why he is prepared to do that."

Bishop Oliveri, who is described as a fervent traditionalist who once celebrated a three-hour Mass in Latin, has not been accused of a crime but refuses to comment publicly on the scandals plaguing his diocese.

Instead, a group of 10 priests rallied around him and published an open letter last week in which they said the investigation was "painting a distorted picture of our diocesan life", adding: "Our church is united around the bishop."

Since being elected in March 2013, Pope Francis has shown that he has little patience for figures within the Church who transgress.

The Pontiff has already sent Adriano Bernardini, an apostolic nuncio, or ambassador, to conduct a preliminary investigation into the scandals that have allegedly unfolded in Bishop Oliveri's diocese.

The large number were brought to the Vatican's attention by parishioners, including a doctor, Luisa Bonello, who delivered a dossier of complaints to the Pope in February. She committed suicide last month, a death that is currently under investigation.

Fr Bardini said he has even witnessed priests behaving criminally and has reported them to Bishop Oliveri, only for his complaints to be ignored. "On three occasions I have reported the bishop to his superiors, to Rome, but nothing has come of it until now," he said. "At last let's hope that truth is brought to light and the diocese is cleaned up once and for all."