Los Angeles Clippers small forward Matt Barnes hit out at the NBA and Phoenix Suns owner Robert Sarver, after being fined $25,000, allegedly for swearing at a fan.

The NBA announced on Tuesday that Barnes had been fined for "inappropriate language toward a fan" during the Clippers' 120-100 victory over Phoenix on Sunday.

But Barnes rubbished the league's allegation on Twitter, admitting that he had used swear words on court but that it was instead directed at Sarver - the banking mogul who has owned the Suns since 2004.

According to Barnes, Sarver had instigated the verbal stoush and had also used inappropriate language.

"Another 25k! The part of the story the NBA hasn't told you was my language wasn't directed at a fan," Barnes wrote.

"I was talking to the owner of the Suns, who was sitting on the baseline and I only said something to him AFTER he 'cussed' [swore] at me BUT because I didn't SNITCH I get fined!"

Barnes followed that tirade with "#thecode" - implying Sarver should have left the incident on the court - before lashing out at the NBA again.

The 34-year-old clearly believes he is being punished for inconsequential indiscretions.

"I've been fined 50k in the last month for kicking a PAPER Gatorade cup that had a little bit of water in it that didn't even hit anyone and responding to an OWNER, who cussed at me first," Barnes wrote.

"50,000 dollars for that?? Come on now!"

"I might need to find a second job with all these crazy tecs [technical fouls] and fines. I can see it now: LA TIMES...'Costco worker by day NBA player by night'."