The daily Liberation and France Inter radio accessed the transcript from a judicial hearing last month in which the accountant, Gerard Limat, said the money was delivered by a Swiss financial services firm between 1995 and 2012.
The 89-year-old Dassault is accused of operating an extensive system of vote-buying that influenced the outcome of elections in Corbeil-Essonnes, a suburb south of Paris, where he was mayor from 1995 to 2009.
Dassault is a senator and CEO of Dassault Group which holds a majority stake in Dassault Aviation that makes commercial and military aircraft, including the Rafale fighter jet.
“It was all in bundles of 100 euro bills,” Limat told the judges, adding that the money was wrapped in newspaper and delivered in plastic bags.
Limat, 74, said the deliveries were organised by Cofinor, a firm which specialises in moving money in and out of Switzerland.
“Cofinor would set a meeting not far from the Arc de Triomphe,” Limat told the judges. He said there were 33 such deliveries and they used the code-names ‘Romano’ and ‘Gerard’ to identify each other in the street.
"I never saw the money as I went straight to the roundabout" of the Champs-Elysees, where Dassault's headquarters is located.
"I went up to the office of Serge Dassault, I placed the bag in a corner of his office and immediately we spoke of other things.
"I never asked questions and Serge Dassault never told me anything. He told me he needed to see me, I understood that he needed cash."
Dassault is listed by Forbes as France's fourth richest man with an estimated net worth of14.6 billion euros.
Limat denies knowing how the cash was used.
Dassault was charged in April with vote buying, complicity in illegal election campaign financing and exceeding campaign spending limits.
The charges relate to three elections in Corbeil in 2008, 2009 and 2010, which were won either by Dassault or his successor and close associate Jean-Pierre Bechter.