The appeal against Harvard University's so-called Oncomouse patent, the first ever granted for a transgenic animal, was launched by six organisations from Austria, Britain, Germany and Switzerland.

Using the Oncomouse technique, scientists can alter a gene in the rodents and make them more likely to develop tumours, which means they can be used to test whether a material might contain carcinogens.

The six groups claim that the patent is "contrary to public order and morality" and that it does not meet some of the requirements of patent law.

The environmentalist group Greenpeace, which is not involved in the appeal, also staged a protest as the first day of the oral hearings got underway at EPO headquarters in Munich, southern Germany.

"The public was deliberately deceived and laws were bent in favour of industry" when it was issued said Greenpeace gene expert, Christoph Then, in a statement.

"In reality, the cancer mouse was just a way to open the door for the gene industry to acquire patents on lives," he said.

A ruling on the appeal could come on Friday, when the final oral hearing is scheduled to take place.

The EPO is responsible for the practical functioning of the patent system in Europe involving the 28 countries that have signed up to the European Patent Convention.

TERRA.WIRE