(BBC) – Chelsea have been banned from signing any new players until January 2011 by football’s governing body Fifa.
The Premier League club was found guilty of inducing French winger Gael Kakuta, 18, 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,’ according to a statement on Fifa’s official website.
Chelsea can appeal against the decision to the Court of Arbitration for Sport.
Fifa’s dispute resolution chamber (DRC) ruled Kakuta must pay compensation of 780,000 euros (£682,000), for which Chelsea are “jointly and severally liable”.
A spokesman for the London club told BBC Sport they were looking into the matter and hoped to issue a statement shortly.
Lens lodged a complaint with world football’s governing body after Chelsea had signed the winger two years ago.
Now the resolution chamber has ruled Kakuta breached his contract with Lens and that Chelsea induced him to do so.
Fifa’s statement continued: ‘The French club had lodged a claim with Fifa seeking compensation for breach of contract from the player and requesting also sporting sanctions to be imposed on the player and the English club for breach of contract and inducement to breach of contract.
‘The resolution chamber found that the player had indeed breached a contract signed with the French club. Equally, the resolution chamber deemed it to be established that the English club induced the player to such breach.’
Chelsea must pay additional ‘training compensation’ of 130,000 euros (£114,000) to Lens, while the player has been banned from playing in official matches for four months.
Kakuta ended 2007/8, his first season with Chelsea, as the youth team’s top scorer and was voted the academy’s player of the year.
He played five times for the youth team and twice for the reserves in his second season before it was brought to an abrupt end in February when he suffered a double fracture of his ankle.
The Lille-born youngster has never played for Chelsea’s first team although he is back to full fitness and has been featuring in the reserves this season.
The next transfer window is open January 1-31 2010 and then again from the end of the season until August 31 (Europe) and September 1 (Britain) 2010.
Lens president Gervais Martel said he felt the judgement was fair and would send out a warning message to larger clubs like Chelsea who break the rules.
‘We expected this kind of decision. The player was under contract with us, and they came and stole him away from us,’ he said.
‘Chelsea didn’t follow the rules. They contacted the player when he wasn’t even 16 yet and while he had been contracted to our training group from the age of eight.
‘The financial sanction isn’t over the top given the nature of the infringement, but it’s really quite significant when it comes to not being able to recruit players.
‘It’s an important message given that protecting up and coming youth players who are contracted to clubs is an issue being followed closely by Uefa president Michel Platini.”
Fifa punished Switzerland’s FC Sion for a similar offence in April and the club was told it could not sign players until the 2010 offseason.
This was punishment for their actions in luring Egypt goalkeeper Essam El Hadary in 2008 before his deal with Al-Ahly had expired.
Like Kakuta, El Hadary received a four-month ban from playing.
Sion have appealed to CAS, which has frozen the sanctions while it considers the case, allowing the club to trade before the current season began. A ruling is expected later this year.
Meanwhile Uefa, European football’s governing body, is keen to introduce a rule preventing the international transfer of players under the age of 18 after member associations, clubs, leagues and players agreed to the principle.
Speaking in March, Uefa president Platini: “The question of minors is above all a moral and ethical issue. We have a duty to take concrete steps to protect young players and training clubs.”