If you read the Gaurdian article that someone linked the confirmation was needed because his remains were transported under some secrecy multiple times. Origin

If you read the Gaurdian article that someone linked the confirmation was needed because his remains were transported under some secrecy multiple times. Originally he was buried in Hispaniola where today is the city of Santo Domingo in the Dominican Republic. Motivated by fear of their destruction, they were moved to Cuba in 1795 under secrecy when France took over the island following several revolts. When Spain lost the Spanish-American war and ceded Cuba in 1898 they were then transported to Seville. Various conspiracy theories arose that the remains were never truly moved out of Santo Domingo, fueled by the fact that the remains in Seville were only partial and hand bones were found in a box in Santo Domingo with an inscription claiming they belonged to Columbus. The researchers note that the hand bones could also be authentic with his remains split between Spain and the Dominican Republic.