Chelsea have been banned from signing any new players in the next two registration periods by Fifa.
The Premiership club was found guilty of inducing French teenager Gael Kakuta to breach his contract with Lens when he joined in 2007.
"Chelsea is banned from registering any new players for the two next registration periods," a statement on Fifa's website read.
Chelsea are looking into the matter and hope to issue a statement.
More to follow.