Vatican City, Jul 3, 2019 / 10:50 am (CNA).- Pope Francis gave unexpectedly a reliquary containing what are believed to be bone fragments of St. Peter to Orthodox Patriarch Bartholomew, an ecumenical gesture that has generated controversy among some Catholics.

The pope took the reliquary from the chapel in the papal apartments, where Pope Saint Paul VI had placed the bronze reliquary containing eight bone fragments after they were discovered in a 1952 dig under St. Peter’s Basilica.

A delegation from the Ecumenical Patriarchate of Constantinople were guests at the June 29 Mass in St. Peter’s Basilica for the feast of Saints Peter and Paul, as has been customary in recent years.

After the Mass, Pope Francis brought Eastern Orthodox Archbishop Job to a chapel in the papal apartments and offered the chapel’s reliquary as a gift, according to Vatican News. The bronze box bears the inscription, “From the bones found in the hypogeum of the Vatican Basilica, which are believed to be of Blessed Peter the Apostle.”

Pope Francis had previously brought the bronze reliquary containing the purported bone fragments for public veneration in St. Peter’s Square on Nov. 24, 2013 at a Mass for the feast of Christ the King, where Eastern patriarchs were also present.

At the time of the public veneration in 2013, Vatican spokesman Fr. Federico Lombardi said, “There is a serious possibility these are St. Peter’s bones, but we do not go beyond that.”

The bone fragments were discovered in an excavation of tombs under St. Peter’s Basilica near Greek graffiti dating back to the year 160 that read, “Peter is here.” Analysis of the bones found that they belong to a man around 60 to 70 years old, and that had been wrapped in a purple cloth woven with gold.

On June 26, 1968 Paul VI said that the bones had been “identified in a way which we can hold to be convincing … we have reason to believe that the few but sacrosanct mortal remains of the Prince of the Apostles have been traced.”

The Orthodox delegation brought the reliquary to Istanbul, where Monsignor Andrea Palmieri, undersecretary of the Pontifical Council for Promoting Christian Unity, personally gave it to Patriarch Bartholomew.

Bartholomew, as Patriarch of Constantinople, is regarded as “first among equals” within the Orthodox communion, and is at least seen by many as the worldwide leader of Orthodoxy.

Orthodox Archbishop Job called the gesture “another gigantic step towards concrete unity.” However the move has generated controversy among Catholics.

Pope Francis said in his meeting with the ecumenical delegation June 28: “The feast of Saints Peter and Paul, which falls on the same day in the liturgical calendars of East and West, invites us to renew the charity that generates unity.”

“I am increasingly convinced that the restoration of full unity between Catholics and Orthodox will come about through respect for specific identities and a harmonious coexistence in legitimate forms of diversity. The Holy Spirit, for that matter, is the one who creatively awakens a multiplicity of gifts, harmonizes them and brings them into authentic unity,” the pope told the Orthodox leaders.

“I consider it valuable in our encounters to share our roots, to rediscover the goodness that the Lord has sown and made grow in each of us, and to share it, learning from one another and helping each other not to fear dialogue and concrete collaboration,” Pope Francis said.