I found this interesting. This is from the book Sisu by Oskari Tokor.
"The trip back was made moer rapidly - but I almost lost my youngest son. Late in the night, beyond Perm, the train was stopped at some wayside station and surrounded by Red militia. They searched the train with great thoroughness. The passengers learned that they expected to find the Czarevitch Alexei, the Czar's 13-year-old son, who had escaped from Jekaterinburg!
"My son was sharing a compartment with our imterpreter. As soon as the militia saw the boy the pounced on him. He was the same age, and the same height, and - they declared - he looked the same as teh Czarevithch. The interpreter tried to assure them tha the boy was Finnish and did not even speak a word of Russian, but no one would believe him. Finally the interpreter remembered that the Czarevitch was said to be lame, and he came up with his last trump. My son was marched up and down the corridor, and everyone watched closely to see if he limped. When the militia were convinced he walked straight on his own two feet, they let him go.
"Every compartment, every corner, of the train was searched, and the pillows and mattresses so thoroughly bayonetted that not a mouse could have remained alive in them. Perhaps the son of Czar Nicholas II succeeded in escaping. Perhaps he remained somewhere among the living when his family was executed behind the tall plank fence surrounding the villa in Jekaterinburg."
pp. 176-177.