Fetal stem cell research became a craze on the left when it appeared that it could be used to justify "harvesting" of fetuses, thereby reinforcing the notion that human beings in utero are objects to be used for the benefit of others. Those anti-abortion activists who criticized the use of fetal stem cells were pilloried as anti-science, standing in the way of cures for Parkinson's Disease and much more.

A boy treated with foetal stem cells for a rare genetic disease has developed benign tumours, raising questions about the therapy's safety.

The boy, now 17, received the stem cells in 2001 at a Moscow hospital and four years later scans showed brain and spinal tumours, PLoS Medicine reports.

Israeli doctors removed the abnormal growth from his spine and tests suggest it sprouted from the stem cells.

Critics say the finding is evidence against the controversial therapy.

Apart from the ethics of using cells taken from embryos, opponents say there are big safety concerns.  ...

Stem cell scientist Dr Stephen Minger, of King's College London, said it was clear that the tumours had arisen from the transplanted cells.

"This is worrying and we have to be cautious. We need to have long term monitoring and follow up of the patients given stem cells and rigorous regulation of centres providing cell therapy.

"Although this is just one case it does show that we need to be careful about the cell populations we are using." He said not all clinics used good quality cells.