A bloodstained tunic belonging to Thomas Becket could be returning to Canterbury for the 850th anniversary of the famous martyr’s death.

The shirt, which has been kept in the Vatican’s Basilica of Santa Maria Maggiore for more than 500 years, is thought to have been worn by the former Archbishop when he was murdered in the city’s Cathedral in 1170 after a row with King Henry II.

It is now one of a number of artefacts linked to Becket which Canterbury Cathedral hopes to display in a series of commemorative events in 2020, including a major church service, which also marks 800 years since the creation of his shrine.

After being martyred, the Archbishop was made a saint by Pope Alexander III, drawing thousands of pilgrims to his place of death. But the Reformation led to his shrine being destroyed in 1538 under the orders of Henry VIII, meaning that little now remains of Becket’s body or belongings.

The tunic, however, survived because 50 years earlier, it had been given to the then-pope by Henry’s father, Henry VII and taken to Rome.

A reliquary containing the garment, which was worn to celebrate mass, was opened and examined in 1992 by experts from the University of Munich, who confirmed it would have dated from the mid-12th century and had been made for a “tall man” matching contemporary descriptions of Becket.

The garment has returned to Canterbury once before, when it was displayed at the Cathedral for the 1,400th anniversary of the arrival of St Augustine in Kent in 1997.

Canterbury Cathedral spokesman Jane Walker said: “The tunic is one of a number of pieces we are looking at to commemorate the Becket anniversary in 2020. We are still waiting for final confirmation, but we would be very excited to see it back here.

The loan is being negotiated between the Vatican and the Church of England, and would need approval by Cardinal Gianfranco Ravasi, the Vatican’s culture minister.