The fabrication and sale of saintly relics was quite a profitable medieval industry. Kings and princes vied with each other to possess the most biblically prominent relics (fragments of the true cross, bones of the apostles, etc.). But St. Andrew was reputed to have been crucified in the Greek town of Patras having preached along the Black Sea coast and up into Scythia (modern Russia) and as far north as Kiev in the Ukraine. So it is quite possible these relics, returned to Orthodox hands by the Roman Catholic Church in the 1960’s, may well be legitimate. Ultimately, who can really know?