Williams, O'Connor face disciplinary action
The 35-year-old Williams, who plays for Top 14 champions Racing 92, has been charged by French police with buying cocaine, and Toulon's O'Connor, 26, with possession of the drug.
"The President of the LNR has approached the League's disciplinary commission to initiate proceedings against the two players," the French National Rugby League (LNR) said in a statement.
"Ali Williams and James O'Connor will be called before the Commission at a date which will be communicated later," it added.
The pair were arrested at 03.00 on Saturday, February 25 outside a nightclub near the Champs Elysees in possession of 2.4 grams (0.08 ounces) of the substance.
Both have been suspended by their clubs.
Agence France-Presse