Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[106] But Caesar, who knew perfectly well the lineaments of Alexander's face, because he had been accused by Herod before him, discerned the fallacy in his countenance, even before he saw the man. However, he suffered the agreeable fame that went of him to have some weight with him, and sent Celadus, one who well knew Alexander, and ordered him to bring the young man to him. But when Caesar saw him, he immediately discerned a difference in his countenance; and when he had discovered that his whole body was of a more robust texture, and like that of a slave, he understood the whole was a contrivance. But the impudence of what he said greatly provoked him to be angry at him; for when he was asked about Aristobulus, he said that he was also preserved alive, and was left on purpose in Cyprus, for fear of treachery, because it would be harder for plotters to get them both into their power while they were separate. Then did Caesar take him by himself privately, and said to him, "I will give thee thy life, if thou wilt discover who it was that persuaded thee to forge such stories." So he said that he would discover him, and followed Caesar, and pointed to that Jew who abused the resemblance of his face to get money; for that he had received more presents in every city than ever Alexander did when he was alive. Caesar laughed at the contrivance, and put this spurious Alexander among his rowers, on account of the strength of his body, but ordered him that persuaded him to be put to death. But for the people of Melos, they had been sufficiently punished for their folly, by the expenses they had been at on his account.