The Christian author Hippolytus wrote in the early third century. In the past some have believed that he was Bishop of Portus, but that is unlikely. He was an anti-Pope and rival of pope Callistus.

Elenchos, or Refutatio Omnium Haeresium (Refutation of All Heresies) 9,7
Callistus happened to be a domestic of one Carpophorus, a man of the faith belonging to the household of Caesar. To this Callistus, as being of the faith, Carpophorus committed no inconsiderable amount of money, and directed him to bring in profitable returns from the banking business. And he, receiving the money, tried (the experiment of) a bank in what is called the Piscina Publica. And in process of time were entrusted to him not a few deposits by widows and brethren, under the ostensive cause of lodging their money with Carpophorus. Callistus, however, made away with all (the moneys committed to him), and became involved in pecuniary difficulties. And after having practised such conduct as this, there was not wanting one to tell Carpophorus, and the latter stated that he would require an account from him.

Callistus, perceiving these things, and suspecting danger from his master, escaped away by stealth, directing his flight towards the sea. And finding a vessel in Portus ready for a voyage, he went on board, intending to sail wherever she happened to be bound for. But not even in this way could he avoid detection, for there was not wanting one who conveyed to Carpophorus intelligence of what had taken place. But Carpophorus, in accordance with the information he had received, at once repaired to the harbour (Portus), and made an effort to hurry into the vessel after Callistus. The boat, however, was anchored in the middle of the harbour; and as the ferryman was slow in his movements, Callistus, who was in the ship, had time to descry his master at a distance. And knowing that himself would be inevitably captured, he became reckless of life; and, considering his affairs to be in a desperate condition, he proceeded to cast himself into the sea. But the sailors leaped into boats and drew him out, unwilling to come, while those on shore were raising a loud cry. And thus Callistus was handed over to his master, and brought to Rome, and his master lodged him in the Pistrinum.

Translation: Early Christian Writings.