A man suffering from leukaemia has become the first adult in Britain to undergo a life-saving bone marrow transplant using blood from a baby's umbilical cord, it emerged today.

Male nurse Stephen Knox, 31, underwent the treatment - which has previously only been performed on children - after being given just months to live.

The procedure was developed by Professor Stephen Proctor, who used stem cell blood from discarded placentas and umbilical cords, which has been used in the past to treat children with serious blood disorders.

Prof Proctor, based at Newcastle Hospital Trust's Haematology Unit, and at Newcastle University, discovered a way to bulk up the stem cells using blood which does not match the sufferer's.

The operation was carried out on Mr Knox, of Middleton-St-George, near Darlington, County Durham, who earlier this year was given just months to live after various chemotherapy sessions failed to stem the leukaemia.

Mr Knox was given treatment to kill off his own bone marrow and then injected with the mixed cord blood which has grown into new bone marrow.

Prof Proctor said it was still early days regarding the pioneering bone marrow operation - but Mr Knox had responded well to the treatment.

Mr Knox, who underwent the procedure in February and is now in remission, is still recovering in hospital.

Prof Proctor said: ''This treatment was his only hope.

''Stephen is progressing much better than we thought he would and the transplant has worked much better and more quickly than we expected.

''It's a really exciting development and opens up huge possibilities.

''It has been carried out 23 times in the UK on children but never with an adult.''

Until now the small quantities of blood collected could not be used for adults because they yield only a few drops of the vital stem cells which, when transplanted, grow into new bone marrow.

Prof Proctor and his transplant team have spent years researching how to bulk up the stem cells, which do match the sufferer's own tissue type, by using cord blood which does not.

Cord blood is blood that is taken from the placenta which supplies the baby with oxygen and nutrients while it is in the womb.

After the baby is born, midwives clamp the umbilical cord and insert a needle close to the placenta so the blood can be collected and after it has been screened it is frozen and can be kept for up to 10 years.

The cord blood bank in Newcastle upon Tyne is one of just two centres in the country with the other in north London.