An autopsy has confirmed that Tony Ayala Jr. died of a heroin overdose.

The Bexar County Medical Examiner's Office revealed the cause of death. The report also cited an enlarged heart as another significant finding.

San Antonio police had suspected a heroin overdose killed the 52-year-old former middleweight contender, whose body was found at his family's gym on May 12. Heroin and a syringe were found next to his body.

According to officials, a woman close to Ayala told police that she and Ayala had quarreled in a house they shared the night before his body was found. Police arrived to find the woman weeping over his body.

Ayala was regarded as a top middleweight contender with a record of 31 wins, 27 knockouts and 2 losses overall. His career came to stop when he was arrested for rape in New Jersey in 1983, and once convicted he then served 16 years in prison before being released in 1999.

He staged a comeback once released and had eleven fights before his career once against came to halt in 2003, as he was once again incarcerated in 2004. The troubled fighter served 10 years in prison in Texas as a result of a parole violation. It was during that 11-fight run when he suffered his only two career defeats, to Yori Boy Campas and Anthony Bonsante.