A race against time is now on to find a bone marrow match for a four-year-old Bradford boy after test results revealed his sister is unable to help him.

Little Billy Broxup has acute myeloid leukaemia and his best chance of survival lay with his eight-year-old sister, Amy-Jo, donating her bone marrow for a transplant.

But after a nail-biting wait for the results to come through, his parents, Claire Broxup, 26, and her partner James Farndale, 22, of Blackshaw Drive, Buttershaw, have been devastated by the news Amy-Jo is not a match.

They are now at Billy's bedside at St James's Hospital, Leeds, while he has gruelling chemotherapy and is intravenously fed antibiotics.

His aunt Victoria Broxup, also of Buttershaw, said the news had come as a shock.

"We kept trying not to pin our hopes on Amy-Jo being a match, but sometimes you couldn't help it," she said.

"The next option now is to find an anonymous donor. The bone marrow register is world-wide so, fingers crossed, we will be able to find one.

"We are still waiting for the tissue results to come back which will tell us if Billy's tissue type is common or rare. Hopefully it will be common as this will increase the number of potential donors."

However, the family are realistic about the chances of finding a donor. "There is still a chance that not one of them will be a match for Billy," said Victoria.

Billy was diagnosed with the rare and life-threatening form of leukaemia in September last year. After six months of chemotherapy his illness went into remission and he was able to go home.

But the family were dealt a new blow in July when they were told it had returned. Before he began his second round of chemotherapy and radiotherapy the family enjoyed a holiday organised by the charity Candlelighters.

Now the family have launched a fundraising campaign for Billy and the charity and have already raised £300, with a further £600 pledged.

Victoria and Billy's grandmother June Broxup have organised a day of fundraising on August 15 at Yorkshire Building Society, Rooley Lane, Bradford, where they both work.

Pete Snowden, member relations manager, has agreed to have his head shaved and hopes to raise £1,000.

And with a blood donor session taking place at the Yorkshire Building Society on Friday, Victoria is busy persuading people to put their names on the bone marrow register.