French police may choose to make an example of ex-All Black Ali Williams and former Wallabies star James O'Connor.

The pair are in custody after an alleged cocaine deal in Paris, in which they were caught with two grams of the drug.

France correspondent Catherine Field said first time personal use could incur a fine of $5500 or a one-year jail term.

But she told Rachel Smalley French police have been cracking down over the past five year, especially at high-end night clubs..

"They might decide to go for the possibility of five years in prison and the much bigger fine of 75,000 Euros."

Ms Field said it's up to the state prosecutor to decide if this will be fast-tracked through the courts because it was a small amount for personal use.

"Or whether it will be a larger court appearance simply because both Williams and O'Connor are public names here in France, and are seen as role models for lots of people."