Chelsea believe Traore was the subject of an option agreement which allowed him to play in friendly games.
FIFA rules prohibit the international transfer of a minor (an under-18), with Real Madrid and Atletico Madrid earlier this month handed transfer embargoes for the next two complete windows after breaching the regulations.
Both clubs plan to contest the sanctions.
Barcelona were placed under a transfer embargo for infringing the same rules in 2014 and have only this month been allowed to register players again.
A FIFA spokesperson told the Press Association: "We are not in a position to comment on any investigations that are ongoing so as not to compromise the process, nor do we provide any comments as to whether or not any investigations are under way."
Asked for comment by the Press Association, Chelsea said: "Bertrand Traore was registered by Chelsea FC in January 2014 in compliance with FA and Premier League Rules.
"Prior to that date, he was party to an option agreement which enabled the club to acquire his registration in January 2014.
The option agreement was registered with, and approved by, both The FA and the Premier League.