An ice pick used to assassinate Russian revolutionary Leon Trotsky may have surfaced in Mexico, still bloodstained 65 years after his murder.
Trotsky's grandson wants the ice pick to be donated to a museum
Ana Alicia Salas, the grand-daughter of a secret policeman who probed Trotsky's death in Mexico City, says she has it.
But Trotsky's grandson has told the BBC that he will not deal with Ms Salas if she is only looking for profit.
He says he will have a blood test only if she donates the ice pick to a museum based in the house where Trotsky died.
Leon Trotsky was a key Bolshevik figure in the Russia Revolution, helping to overthrow the Tsarist regime in Russia and becoming an influential figure in the early days of the Soviet Union.
He was forced into exile in the 1920s after losing a power struggle with eventual Soviet leader Joseph Stalin.
In 1940, a Spanish-born Soviet agent, Ramon Mercader, murdered Trotsky at his home in Mexico City.
Sixty-five years later, reports that the murder weapon has resurfaced have re-ignited long held passions.
"If she wants to make business with this object then I really don't collaborate with her," Mr Volkov, who saw his grandfather dying of his wounds, told the BBC.
"If she wants to give it to the museum freely I will give a blood test," he added, pointing out that others have claimed to have the weapon in the past.
Leon Trotsky founded the Red Army and the Politburo before exile
Mr Volkov described how as a young boy he returned from school to find his grandfather injured and dying.
"There were police outside the main entrance. There was a car badly parked outside the house.
"I had a feeling of anxiety, [that] something serious, something grave had happened."
Inside, he found a seriously wounded Trotsky, who died the next day in hospital.
According to legend, even after the ice pick was embedded in his forehead, the intellectual son of a Ukrainian farmer fought back.
Trotsky grappled with his assailant before moving to an adjacent room, where he collapsed on the floor.
While Mr Volkov would like the ice pick donated to the museum if it is proved to be the murder weapon, others are not so sure.
"I personally would not like the murder weapon in the museum," Beatrice Lopez, who works as a guide there, told the BBC, although she admitted it would boost visitor numbers.
"I think the murder weapon would attract fanatics and I think it would be dangerous to have it here."