The point here is this. Someone very well may have claimed the child as a dependent illegally. There is absolutely nothing and no way physically possible to prevent it. So if you are the one entitled to claim them, go ahead and do so. When the IRS receives your tax return and becomes aware the child has been claimed on two tax returns now, they will contact both claimants (by mail) asking for proof that you have the right to claim them. Since the other claimant is overseas and your child is not, simply producing a passport (if the dependent has one) or proof that the child has no passport (assuming the child is a U.S. citizen) will most likely suffice. But in the letter you will receive from the IRS, they will provide instructions on what you need to do to prove your right to claim the dependent.
