The forearm is generally kept in a silver box within the main Jesuit church in Rome, II Gesu, and rarely allowed to be moved.

But it will be brought to Australia on September 16 and will visit St Francis Xavier College in Florey and St Christopher's Cathedral later that month.

One of the patron saints of Australia, St Francis Xavier worked as a missionary in Asia and was one of the founders of the Jesuit order of Catholic priests and brothers.

He died in 1552, although his right forearm was not removed until 1614, the body part chosen because he used it to bless and baptise thousands of people.

St Francis Xavier's body was moved several times after his death, but most of it is now kept in India, with several other relics located throughout the world.

Cathy Moffit, from the Archdiocese of Canberra and Goulburn, is organising the local part of the tour. She likened visiting a relic to visiting a gravesite, and said Catholics may like to pray in its presence.

''It gives people an opportunity to honour the saint and learn more about the saint,'' she said.

Ms Moffit said the relic would be housed in a perspex-fronted box 1.5 metres long and would be moved from one location to another in the back of a hearse.

Pall bearers will move the forearm from the hearse to churches and halls, and a Jesuit priest or brother will accompany it from place to place. The relic's visit to Australia is part of the celebration of the Year of Grace.