Barcelona will not be allowed to sign any players in 2015 after the Catalan club's appeal against their transfer ban was dismissed by the Court of Arbitration for Sport.
The Primera Division outfit turned to CAS in August after FIFA rejected their appeal to overturn a two-window ban, which was handed to them by world football's governing body in April due to concerns over the "international transfer of minors".
But their quest hit a further dead end on Tuesday, meaning they will be unable to bring in any new blood until January 2016.
"The Court of Arbitration for Sport (CAS) has dismissed the appeal filed by FC Barcelona against the Federation Internationale de Football Association (FIFA) regarding the decision issued by the FIFA appeals committee on 19 August 2014," a statement from CAS read.
"In such decision, the Spanish football club was sanctioned with a transfer ban for two periods, a fine of CHF 450,000 and a reprimand after it was found to have infringed the FIFA regulations with respect to the registration of a number of minor players."
Barcelona were found guilty of breaching FIFA's rules on the transfer of players aged under 18. The players in question were registered and participated in competitions with the Catalan club between 2009 and 2013.
The CAS statement continued: "The panel found in particular that FC Barcelona had breached the rules regarding the protection of minors and the registration of minors attending football academies (articles 19 and 19bis of the FIFA regulations on the status and transfer of players).
"Accordingly, the FIFA decision is confirmed in full and the sanction remains in force.
"In view of the need to issue a decision before the opening of the next transfer window, the panel has issued its decision without the grounds. The full arbitral award, with the reasons for the panel's decision, will be issued as soon as possible."
Barca went on a summer spending spree this year while the suspension went on hold during the appeals process, splashing out more than 150million euros on Luis Suarez, Ivan Rakitic, Marc-Andre ter Stegen, Thomas Vermaelen, Claudio Bravo, Jeremy Mathieu and Alen Halilovic.
But there will be no further new recruits heading to the Nou Camp for at least 12 months, with the CAS ruling the final word on the matter.
Barcelona issued a statement on their official website later on Tuesday morning, expressing their "utter nonconformity with the resolution" and insisting any errors that may have been made were "of an administrative nature" only.
It read: "With all respect for the sports authorities, the club has expressed its utter nonconformity with the resolution.
"FC Barcelona wishes to state, with all due respect for the sports authorities, that it totally disagrees with the verdict of the Court of Arbitration for Sport (CAS) announced today to confirm the sanction originally imposed by FIFA as a consequence of the alleged breach of regulations on the international transfer of minor footballers.
"The club has made it clear to the FIFA disciplinary commission, the FIFA appeals commission and the CAS itself that it understands and supports the policy on the protection of minors and the concern for the protection of their development and education.
"This is confirmed by how the club has acted throughout its history, setting an example around the world for the way its young footballers are schooled and educated, and the work that is done on their development. FC Barcelona's youth structure has enabled hundreds of young players to achieve their dreams and receive a decent upbringing.
"The errors that the club might have committed, and which have been recognised and argued before the corresponding authorities, are, in all cases, of an administrative nature and to a large extent have been caused by the existing conflict between the FIFA regulations and Spanish legislation, along with the club's conviction that it was acting correctly.
"Therefore, FC Barcelona considers the sanction to be completely disproportionate as it supposes an excessive punishment for the club, when considering its trajectory and the circumstances of this specific case."