The head of the Vatican's doctrine office is suggesting little new will come from a study commissioned by Pope Francis into the role of women deacons.

Cardinal Gerhard Mueller says the Vatican is putting together a list of experts for the study. But he says the focus will be historic in nature, studying the role of women deacons in the early church, and that regardless a comprehensive study was completed in 2002.

That study found that female deacons of the early church cannot be compared to the ordained male diaconate of today.

Francis made headlines when he agreed to a request by a nun to set up the commission

Ordained deacons aren't priests but perform many of the same functions as priests, such as presiding over baptisms, marriages and funerals.