Alexander's treasurer who later fled with the royal treasury was Harpalus. A childhood friend of Alexander, Harpalus was appointed treasurer of the empire at Babylon in 330 BCE, despite being unable to take part in the campaign because of a lame leg.
Harpalus was responsible for vast imperial funds while Alexander campaigned across Asia. He repeatedly fell out of favor and was accused of absconding with money. In 324 BCE, he fled Babylon for Athens with a large amount of the royal treasure, reportedly carrying hundreds of talents and seeking protection from Alexander's enemies.
His arrival caused the famous Harpalus Affair in Athens. The Athenians imprisoned him and placed his money under official guard, but Harpalus escaped and eventually fled to Crete, where he was killed in 323 BCE. The affair also triggered a political scandal involving the Athenian statesman Demosthenes. Philoxenus was an official involved in pursuing Harpalus, not the treasurer himself; Nicanor and Cleomenes held other roles in Alexander's administration.