Salaam every body.

Recently, I read on some Christian site which claims that the prophet Mohammad (pbuh) had sexually molested a girl of 6 years old. They are calling him a paedophile? Can someone please explain this, is it true? And if so what is the justification for such a thing. Thank you very much, and please someone answer this question for me, as I am very hurt by what I have read. And I know in my heart that there is a plausible explanation to this, or a simple misunderstanding on the part of the Christians who do tend to fabricate many things. Please can someone provide info that disproves this argument. Thanks you very much.

salaam