The frontrunner in the French presidential election, Nicolas Sarkozy, has been attacked by rivals for comments he made about paedophiles.
Nicolas Sarkozy hit back at Jean-Marie Le Pen over immigration
Socialist candidate Segolene Royal said his view that some people were "born paedophiles" was "extremely serious".
Mr Sarkozy, formerly interior minister, leads the ruling centre-right UMP and is tipped to win the first round on 22 April and second round runoff on 6 May.
He has also rowed about immigration with the far-right's Jean-Marie Le Pen.
Centrist candidate Francois Bayrou, currently third in the polls behind Mr Sarkozy and Ms Royal, said Mr Sarkozy's comments about paedophiles were "terribly worrying" and "chilling".
In a weekend interview for Philosophie magazine, Mr Sarkozy said he was "inclined to believe that people are born paedophiles, and it's also a problem that we don't know how to treat this pathology".
On Tuesday, he sought to downplay his comments, rhetorically asking "Who can tell me it's normal to rape a three-year-old boy? In relation to that, what is nature and what is nurture? I would refrain from deciding one way or the other".
Mr Le Pen labelled Mr Sarkozy's comments "absurd".
On the left, the Greens and the anti-globalisation candidate, Jose Bove, accused Mr Sarkozy of preaching "eugenics", while the Communist Party candidate, Marie-George Buffet, said the genetic argument was a "monstrosity" which had served as an ideological basis for Nazism.
Mr Sarkozy has hit back at Mr Le Pen for having said his immigrant origins were a factor in the election.
"I want to say to Mr Le Pen, who has implied that I am not sufficiently French to be president, that yes, I am the child of immigrants. I am the son of a Hungarian and the grandson of a Greek who fought for France in World War I", Mr Sarkozy told a rally in Tours.
"I am a Frenchman of mixed blood who believes that one is French inasmuch as one loves France... France is not a race, it is not an ethnic group".
Mr Le Pen had said Mr Sarkozy was "a candidate who comes from immigration", while he himself was "a candidate of the native soil".