Hopes of finding a miracle DNA match to save dying youngster Kailee Wells were last night cruelly dashed when tests on a man who said he could be her father proved negative.
Defiant mother Linda Wells, 50, said: 'I am disappointed but not defeated.'
The setback comes amid the release of new figures showing the campaign to save six-year-old Kailee Wells had encouraged 10,000 new donors to join China's bone-marrow databank.
More than 20 mainland newspapers and dozens of radio and television stations as well as numerous publications worldwide have been helping to raise awareness of Kailee's plight, which was first reported in the South China Morning Post.
The girl, who was adopted by an American family after being abandoned as a baby, has aplastic anaemia and a bone-marrow transplant is her only hope. Mrs Wells has travelled to the mainland to track down her daughter's biological parents.
On Sunday, Mrs Wells travelled to a laboratory in Beijing with two vials of blood belonging to a former shoe-maker claiming to be Kailee's biological father. But after an agonising two-day wait, last night she learned the truth. The man was not a match, and no match has yet been found among the 10,000 who have answered her appeal.