Daiki Kameda, the second of the three boxing brothers from Osaka and a former world champion in two weight classes, has announced his retirement because of a detached retina in his left eye.

The 26-year-old’s decision comes less than a month after older brother Koki decided to leave the ring, leaving just Tomoki as the only active fighter in the high-profile but controversial family.

According to a boxing source, Kameda suffered the detached retina during sparring in June last year.

He underwent surgery three times and, although was diagnosed as recovered, did not regain the same level of eyesight.

It is said he decided to retire after losing a comeback match in the United States.

Kameda, who made his pro debut in 2006, was vilified after his loss by disqualification in a title fight against WBC flyweight champion Daisuke Naito.

He bounced back to capture the WBA flyweight title in 2010, and became the IBF super flyweight champion in 2013.

But after losing in his first defense of the IBF title in December that year, the Kameda Gym was suspended over improprieties regarding the relinquishing of the belt and he lost his license to fight in Japan, leading him to continue his career overseas.

Kameda has not said anything about his future plans.