Tissue samples from the body of a billionaire Georgian tycoon, Kakha Bendukidze, will be sent from London to Moscow for DNA tests amid a court battle over his fortune.
A High Court judge in London ruled in favour of Anastasia Goncharova, a 24-year-old King's College graduate, who says she is Bendukidze's daughter.
Bendukidze's widow Natalia Zolotova argued against sending the samples. Ms Goncharova might prove to be the heir.
Bendukidze died in London in November.
Aged 58, he had had heart surgery in Zurich a week earlier.
The tissue samples are being kept under lock and key at Imperial College, London, on the order of a British coroner.
But Judge Thirlwall said that if some samples were not released and sent to Moscow for testing there would be a risk of "grave injustice".
"The results of the testing are overwhelmingly likely to determine paternity. There is no good reason to delay this fundamental step any further," said Mrs Justice Thirlwall on Wednesday.
"The Russian court has ordered that the testing take place now. Further delay will achieve nothing."
Ms Goncharova is embroiled in court cases against the tycoon's widow and his sister Nunu in Russia and Georgia. They both dispute her claim to be his daughter.
Ms Zolotova, who writes for Russian Vogue, said she knew nothing about Ms Goncharova until the latter turned up at Bendukidze's funeral.
The tycoon is reported to have had enormous wealth in Russia. He trained as a biologist and made his fortune in heavy industry in Russia in the 1990s.
In 2004-2008 he oversaw economic reforms in Georgia under former President Mikheil Saakashvili. He also engaged in philanthropy, supporting the Free University of Tbilisi and Agricultural University of Georgia.
Ms Zolotova stood to inherit his riches as his widow until Ms Goncharova contested the claim.
If it were proven that Ms Goncharova was Bendukidze's daughter then she would inherit his fortune, but Ms Zolotova might still be able to stake a claim under Georgian law.