Alejandro Gonzalez Jr, who Carl Frampton fought in the United States last year, has been "executed" in Mexico, according to reports.
The 23-year-old was found dead alongside two others in a jeep near his home in Guadalajara on Friday morning, ESPN reported.
Gonzalez Junior fought Frampton in El Paso, Texas in July last year with Belfast's Jackal retaining his IBF Super-Bantamweight title.
That was despite the Mexican knocking down the Tigers Bay man twice.
Frampton was given the bout after 12 rounds in El Paso, with two judges scoring 116-108 in his favour while the third scored it 115-109.
"One of the nicest guys I've shared a ring with," Frampton said in a Friday night tweet.
After their bout, Frampton described his opponent as a "warrior".
"Gonzalez, though, deserves credit, he was a lot better than I thought," he said.
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