In 1929, during an archeological excavation of Corinth, a first century pavement was uncovered which contains the following inscription: "Erastus, Procurator and Aedile, laid this pavement at his own expense." Was this the Erastus who was the companion of Paul?
The Erastus, who was associated with Timothy as an assistant of Paul, was probably not the city treasurer of Corinth mentioned in Romans 16:23. This Erastus, since Erastus was a common name, was probably a Corinthian freedman who had acquired considerable wealth in commercial activities. This Erastus was an example of the public οἰκονόμος which the RSV translates as city treasurer.
But this explanation does not explain why Paul was sending greetings to Erastus.
Gospel of Luke