The results of a probe into claims that former Palestinian Authority chairman Yasser Arafat was poisoned by polonium will not be known until the end of May at the earliest, the Swiss lab carrying out the tests said Wednesday, according to AFP.

"There are two series of tests that have to be carried out. The first one is complete and we're going to start the second one, so there won't be and tangible results until the end of May," said Darcy Christen, spokesman for the Swiss University Center of Legal Medicine in Lausanne.