By Joshua McElwee

VATICAN CITY (Reuters) - The sanctuary of Lourdes, one of the world's most popular Catholic pilgrimage sites, began on Monday to cover up a series of mosaics made by a prominent priest with ties to the Vatican who has been accused of sexual abuse.

The artwork is by Rev. Marko Rupnik, an internationally known artist, who has been accused by about 25 people, mostly former Catholic nuns, of various types of abuse.

Rupnik, who was expelled from the Catholic Jesuit order in 2023 but remains a priest, is not known to have commented publicly on the accusations. The Vatican in 2023 reopened an investigation into his conduct, which is ongoing.

Mosaics by Rupnik adorn the facade of the Rosary Basilica in Lourdes, near the France-Spain border, where some five million Catholics and other faithful visit each year to experience spring water that is said to have healing properties.

Workers placed large coverings over many of the images on Monday, Lourdes Bishop Jean-Marc Micas said in a statement.

"A new symbolic step needed to be taken to facilitate entry into the basilica for all the people who today cannot cross its threshold," said the bishop, in an apparent reference to clergy abuse victims.

Micas had previously declined to cover the images but ordered in July 2024 that they no longer be illuminated at night.

Laura Sgro, a lawyer representing five of Rupnik's alleged victims, welcomed the covering of the images.

"Every believer, and not just every victim of abuse, must have an open heart when praying, and this cannot happen if they have to kneel before a work of art that was likely the place where abuse was experienced," Sgro said in a statement.

Rupnik's artwork is thought to adorn some 200 churches and chapels around the world, and is also known to adorn at least one chapel at the Vatican.

Vatican officials have largely declined to comment on the allegations, citing the ongoing investigation into Rupnik. 

Cardinal Victor Fernandez, the Catholic Church's chief doctrine official, told reporters earlier this month that he was starting to contact lawyers who could serve as judges in a likely Church trial against Rupnik.

Last week, the Jesuit order began reaching out to some of Rupnik's alleged victims to start a process of offering reparations on a case-by-case basis.

Sgro called the letters a "clear, strong and concrete gesture" and "an important step forward".

(Reporting by Joshua McElwee; editing by Crispian Balmer and Mark Heinrich)