Archbishop Charles Scicluna, who is in Chile investigating accusations that a bishop had covered up the sexual abuse of minors, heard more complaints of sex abuse on Tuesday that could spur fresh Vatican investigations.

Scicluna, the Vatican's most experienced sex abuse investigator, arrived in Santiago more than a week ago to hear complaints that Bishop Juan Barros had hidden information about the abuse of minors by his mentor, Father Fernando Karadima.

Barros, appointed by Pope Francis to the southern diocese of Osorno in 2015, has said he was unaware of any wrongdoing by Karadima.

Scicluna, who was briefly hospitalised for a medical condition, has broadened the scope of his meetings as more victims of sex abuse have come forward, some of whom have alleged they were abused by members of the Marist Brothers Congregation in Chile who asked to meet with him last week.

"We want a special Vatican commission to be created, which analyses, studies, investigates and sanctions all the actions committed by Marists," Isaac Givovich, a spokesman for a group of former students and victims of abuse, told reporters on his way into a meeting with Scicluna.

The Alumni of the Alonso de Ercilla Institute denounced the alleged abuses committed by the Marists in Chile and issued statements in a recent canonical investigation, but they say that process lacked transparency and want to ensure Marists are not involved in any new investigation.

Victims who allege sexual abuse committed by members of the Salesian congregation in Chile said they will also hold a meeting with Scicluna.

Scicluna, who is has been the archbishop of Malta for three years, is scheduled to leave Santiago on Thursday.