Chelsea's protracted move for David Luiz may have collapsed today after Benfica announced they had failed to reach an agreement with the Barclays Premier League champions.
The Blues had yesterday looked set to complete the reported £26m signing of the 23-year-old after the Portuguese giants went public for the first time about negotiations between the parties.
But this afternoon Benfica released a statement on their own website, which read: "Negotiations between Benfica and Chelsea FC, with a view to the possible transfer of David Luiz, were concluded today without the parties having reached an agreement."
The clubs are known to have been in and out of talks for a month, ever since Chelsea had a reported £17m bid for the player rejected.
And although Benfica's statement appeared to signal an end to negotiations, Press Association Sport understands the move could yet be resurrected.
Chelsea's confidence at completing the deal was demonstrated on Wednesday when they successfully applied for a work permit for the Brazil international.
However, with less than four days to go until the end of the window, they are running out of time to thrash out their differences with Benfica.
Proof the clubs were still haggling over the finer points of the transfer arrived when the defender played the whole of his current side's Portuguese Cup win at Rio Ave last night.
The dispute reportedly centres on the precise make-up of the deal, with Benfica unwilling to entertain the fee being paid in instalments.
They are also said to be cool on the idea of a player-plus-cash arrangement, with Nemanja Matic - currently on loan at Vitesse Arnhem - having been mentioned as a possible makeweight.
Luiz, whose contract at Benfica expires in 2015, is widely regarded as one of the most promising defenders in Europe.
He arrived in Lisbon in 2007 and was a key member of the side that last season clinched the Portuguese title for the first time in five years, missing only one of 30 league matches.
His performances earned him a call-up to the Brazil squad for August's friendly against the United States.
He also played against Iran and Ukraine in October and is in the squad for the February 9 friendly in France.