A fish head left in the freezer is the reason Antonio Brown is allegedly stiffing a guy out of $38,000 ... so says the celeb chef who put it in there.
The story is wild ...
Stefano Tedeschi -- who filed a lawsuit against AB just last month -- tells TMZ Sports after cooking for the NFL superstar at the Pro Bowl in 2018, he left a salmon head in the freezer with the intentions of making some soup the next day.
The problem? Apparently, AB and his crew thought it was a threat -- and straight-up kicked him out of their mansion!!!
"The salmon head I thought was a joke," Tedeschi says ... "But, apparently, it was real."
Tedeschi says he had agreed to cook for Brown and all of his friends for 3 days in Florida during Pro Bowl weekend last year.
He says the first day went off swimmingly ... he cooked breakfast and lunch for Antonio and his guys -- and then came back later in the evening to do a big cooking show dinner.
Part of that meal included filleting a salmon -- one Tedeschi had bought with his son earlier in the day. But, when Tedeschi stored the head of the fish in the freezer after the show ... that's when he says all the trouble began.
"Apparently they misunderstood the fish head," Stefano said.
"I said, 'Who could have possibly misunderstood a fish head in the freezer? Tell me, what person with intelligence could have misplaced a fish head for some mob, horse head?!'"
Stefano says when he came back to cook the next day, he was booted from the property and wasn't allowed to retrieve any of his cooking gear that he had left on the premises.
Antonio also didn't allow him to cook the following day ... and, according to Stefano, the receiver never paid him a dime for the weekend.
As we previously reported, Stefano is now suing Brown for $38,521.20 for the weekend, and he tells us all signs are pointing toward an ugly legal battle in court to get the cash.
"AB's team is acting like we're going to go to court ... he's going to drag this thing out, he's got more money than me, blah, blah, blah."
We reached out to Brown's attorney, Darren Heitner, for comment on the fish head story ... and Heitner tells us, "There is no comment on the 'fish head' claim nor any other claim the plaintiff wants to make with the media."
"We are proceeding as previously stated and will be filing our response with the court."