Dio Cassius, Roman History 54.16.1

ὁ δ’ οὖν Αὔγουστος ἄλλα τε ἐνομοθέτησε, καὶ τοὺς δεκάσαντας τινας ἐπὶ ταῖς ἀρχαῖς ἐς πέντε ἔτη αὐτῶν εἶρξε.

As well as other laws, Augustus made one which barred from office for five years those who had given bribes to anyone.