Barcelona have denied a report in El Confidencial which claims the club's former president Sandro Rosell illegally purchased a liver for Eric Abidal in 2012.
In a statement, the Catalan club said the story "omits an important detail by failing to recognise that the case was shelved by a court [earlier this] year."
They added: "This only serves to damage the honourability of Abidal, of all the organisations linked to transplants, of FC Barcelona, and of the club's former president Sandro Rosell.
"The club deeply regrets the lack of rigour in the publication of the information related to such a sensitive topic."
Wednesday's article in El Confidencial detailed how police overheard several Rosell phone calls in which he "implicitly admitted illegally buying a liver" for Abidal.
Those conversations were sent to the judge who is overseeing the money laundering case for which Rosell is currently imprisoned, prompting a separate case to be opened -- organ trafficking is punishable by 6-12 years in jail in Spain.
The judge passed the case on to a regional court in Catalonia, which has corroborated Barca's explanation that the investigation has been closed.
"We received a brief from the National High Court in Madrid a year ago in relation to an alleged criminal activity that claimed to involve Sandro Rosell and the alleged illegal purchase of an organ," the Regional High Court in Catalonia said in a statement .
"The court investigated the matter but no crime or alleged perpetrators could be identified. The investigation, therefore, was closed."
Abidal, appointed as Barca's new sporting director last month, underwent a liver transplant in 2012 when he was still a player at the club, with his cousin donating his organ.
After the transplant, he was sidelined for almost a year, completing a two-year ordeal with illness following the removal of a tumour on his liver in March 2011.
He eventually returned to the pitch but only made a handful of appearances for Barcelona before signing for Monaco in 2013 and then retiring in 2014 after a brief spell at Olympiakos.
Following his battle with illness, he set up the Eric Abidal Foundation, which released a statement in his name later on Wednesday.
"The Eric Abidal Foundation, in our name and that of Eric Abidal, categorically denies the information which has appeared about an irregularity in the treatment of his illness," they said.
"The entire process relating to his transplant followed the established guidelines and protocols.
"We regret that the honourability of everyone involved in the process has been called into question. Eric has professed his great admiration and is enormously thankful for his treatment, especially to his donor, his cousin Gerard."
Abidal has since responded to the reports with a post on his Twitter page, which read: "I feel obliged to communicate my annoyance and sadness in relation to today's news about my alleged illegal liver transplant.
"Out of respect for my family, the medical team and everyone who has undergone a similar situation, I would like to sincerely apologise if at any point there have been doubts about the unsoundness of the news published today.
"My cousin Gerard donated his liver to save my life and for this I am truly grateful to him. Existing procedures and protocols were followed at times and all the medical documentation that proves so is available."