Alex Forger said Friday that Edwards' then-lawyer Wade Smith told him in the fall of 2008 that the former candidate agreed that the $725,000 given by wealthy heiress Rachel "Bunny" Mellon had been provided for his benefit.
Some of Mellon's money was used to hide Edwards' pregnant mistress. Whether Edwards had knowledge of the money is a key question in his prosecution on charges related to campaign finance corruption.
Edwards' current attorney has denied Edwards knew Young had gotten the money from Mellon or that it was being spent on the mistress.
The Associated Press contributed to this report.