The forward was immediately shown a straight red card by official Gil Manzano after getting in his face and shouting at him for ruling that he had fouled midfielder Arthur.
And reports in Spain claimed to have deciphered exactly what he said during the confrontation with Radio Catalunya saying Costa told Manzano: 'I s**t on your f***ing mother'.
And the referee has now confirmed the reports in his official match report.
'In the 28th minute the player Diego Da Silva Costa was sent off for the following motive: he shouted loudly at me the following words: 'I s*** on you w**** mother, I s*** on your w**** mother.
Costa had to be refrained by his team-mates following the dismissal with former Spain team-mate Gerard Pique attempting to calm him down and usher him off the pitch.
Speaking about the incident after the game, his manager Diego Simeone said the red card was fully deserved if that is indeed what he said.'If Costa said that, then the referee was right to send him off,' the Argentine told reporters. 'If he said something so bad in such an important game, then it was right'.
Atletico performed well with 10 men and looked set to leave the Nou Camp with a point before Luis Suarez popped up with a fine strike in the 85th minute.
Lionel Messi then put the game to bed with a trademark solo goal just one minute later, all but bringing an end to the La Liga title race. Ernesto Valverde's men now sit 11 points clear with just seven game remaining.
Speaking after the game, Atletico midfielder Koke said: 'Barca are practically champions. It was a very strange game, we were doing so well until the red card but all the small details went their way.
'Whenever we come here something strange happens, we've had a lot of red cards against Barca and not all of them have been fair. When you have 10 men against one of the best teams in the world it's normal that it's a struggle.'