The European Union's top court decided Tuesday that researchers cannot make scientific patents based on stem cell research techniques that involve killing a human embryo.

The European Court of Justice ruled that destroying human embryo cells for research that could eventually lead to profit is unethical and undermines human dignity.

The decision was a blow to researchers who said embryonic stem cells could help cure incurable diseases.

A representative of the European People's Party commended the ruling because it would force scientists to use other proven methods, like adult stem cells.

"Human embryos cannot be commercialized," European People's Party spokesman Peter Liese said. "They will now choose other ways to address the same problem and I think that is also good for the patients."

"We have already 70 diseases which we can cure with alternatives, with stem cells taken from the adult body and not destroying embryos," he added.

Supporters said the ruling also sets a clear definition of a human embryo, even in its early stages of development.