LONDON: British scientists claimed yesterday to have created human sperm from stem cells but other experts questioned their data.

Researchers at Newcastle University and the NorthEast England Stem Cell Institute say they used a new technique to derive what they described as sperm cells from embryonic stem cells. Stem cells have the potential to become any cell in the body.

Newcastle research leader Karim Nayernia said in a statement yesterday that the technique would allow researchers to study how sperm develops and possibly help develop treatments for infertile men.