Paris: Two centuries after the French people beheaded King Louis XVI and dipped their handkerchiefs in his blood, DNA analysis has thrown new doubt on the authenticity of one such rag kept as a morbid souvenir.

The contents of an ornately-decorated gourd alleged to hold traces of the king’s dried blood has long been the subject of scientific disagreement, with tests throwing up contradictory results.

On Thursday, a team from Europe and the United States said they had sequenced the full genome of the DNA in the squash, and found it was unlikely to be from someone tall or blue-eyed — both features ascribed to the 18th century monarch.

“The results of these analyses do not support the royal identity of the sequenced genome,” the authors concluded in a study in the journal Nature Scientific Reports.

Researchers have been trying for years to verify a claim imprinted on the calabash that: “On January 21, Maximilien Bourdaloue dipped his handkerchief in the blood of Louis XVI after his decapitation” in Paris in 1793.

He is then said to have placed the fabric in the dried, hollow gourd and had it embellished with portraits of revolutionary heroes.

In 2010, a study said DNA analysis of blood traces found inside the ornate vegetable revealed a match for someone of Louis’ description, including his blue eyes.

One of the authors of that paper, Carles Lalueza-Fox of the Institute of Evolutionary Biology in Barcelona, also participated in the latest study, which contradicts the blue-eyed finding.

He told AFP the latest DNA analysis was much more complete: “we have now the whole genome of the person (in) the gourd.”

Lalueza-Fox said about 76 per cent of the DNA in the calabash belonged to a single person whose genetic signature, from northern Italy, was not “compatible” with Louis’ known, more central-European ancestry.

The individual likely had brown eyes and was of average height — contrary to the king’s description as the tallest person in the royal court.

In 2012, Lalueza-Fox had co-authored yet another paper concluding the blood in the gourd was indeed from Louis — based on DNA shared with a mummified head said to belong to the king’s predecessor, Henri IV.