Two centuries after handkerchiefs were dipped in the blood of the beheaded French king Louis XVI, scientists believe they have proved one such rag kept as a revolutionary souvenir contains his bloodstains.

For years researchers have been trying to verify the claim that an ornately decorated calabash contained a blood sample of the king, who was guillotined in Paris on January 21, 1793.

On that day Parisian Maximilien Bourdaloue joined the crowds as dipped a handkerchief into the blood left at the scene of the decapitation.