While personal paternity testing is illegal in France; court issued, official paternity tests aren’t. Each year in the region of 1,500 tests are performed under strict legal circumstances and by the orders of a judge. That’s a drop in the ocean compared to the amount of testing which is undertaken illegally through foreign parties. According to information to be found in Lancet, a British Medical journal, as many as 1 in 3 children are not actually the biological son or daughter of the man who it is commonly believed fathered them.