Cue the spooky music! Seriously I have no dog in this fight. I just find it amazing how people of all backgrounds can believe anything. Maybe this is false (probably is) but maybe it's true. After all, it's not a conspiracy if they really are out to get you.
Or something like that.
I've given some on this thread rough treatment. They deserve it. Richard never behaved as Lord Protector in any way, shape, manner or form. He delayed the coronation of King Edward in order to dig up someone who was willing [although not publicly] to claim the prior king's marriage invalid. Contrary to claims -- falsely -- made on this thread, Richard reluctantly accepted crown. No such thing. He was a legalist, and he arranged a legal coup, manipulated Parliament and got himself crowned.
Those machinations alone tell you that Richard had no respect for the "much-loved" brother to whom Richard's rise in the world was largely owed. Deposing the reigning king with a whisper campaign in front of you and an army at your back is the act of a treasonous villain, not a loving brother. Richard knew that his nephew's claim to the throne were -- and always would be -- stronger than his own. There's no need to ask bizarre questions which lead us into tortured suppositions and theories for which there is no historical evidence, when the obvious answer is so much easier and so much more supported by the facts.
As soon as he met them, Richard IMMEDIATELY had his nephews sent to The Tower. He delayed the coronation. He had Parliament depose the king. He got himself crowned in the space of less than two months. A month later, the princes were never heard from again. Rumors persisted from late summer of 1483 until the end of his short reign that Richard had murdered them. He publicly denied [and thus, publicly acknowledged] the rumors. He never produced any evidence that they remained alive. Had they remained in the Tower, they were already in the one place on earth safest from Henry Tudor. Sending children abroad on a dubious Channel crossing into countries where Richard's writ did not run is a ridiculous idea.
Let's not get too clever about this.