Carter now plays for star French rugby club Racing 92.
Carter, aged 34, signed with Racing 92 after winning his second World Cup with the All Blacks in 2015.
The deal is reported to be the most lucrative contract in professional rugby, estimated at worth more than $2 million a season.
Carter played 112 tests for the All Blacks between 2003-15 and is the highest-point scorer in the history of test rugby.
France-based Radio Sport correspondent Catherine Field warned that French drink-driving laws were much stricter than they have been in the past, when the wine-drinking culture was prevalent.
"There's a real feeling here over the past four or five years that drink driving isn't a good thing to do any more," she said.
"People have realised that picture of France of 30 years ago, when you could go out and have a great lunch and a pastis, and then drive home ... those are the old days. Now, it's very strict.
"[Dan Carter] will probably undoubtedly lose his license. What type of financial penalty will again be up to the judge."
The other imponderable at this stage is how his Racing 92 club will react.
Carter, along with his Racing clubmates - fellow former All Black Joe Rokocoko and Argentina wing Juan Imhoff - were cleared by the French Rugby Federation after proving that the traces of corticosteroids found in their urine samples were down to their being granted therapeutic-use exemptions for prescribed medication as they recovered from injuries.
"This is a very serious offence. Whether they will support him again, that is a big question."
Adidas New Zealand country manager Quentin Bleakley said they were "aware of the reports involving Dan Carter and we won't be making any further comment".
