Four of the five former members of Japan's Self-Defense Forces accused of sexually abusing a colleague in a widely followed case denied the allegations on Wednesday despite a previous apology to the victim, reports said.

The about-face took place during the first hearing in a civil lawsuit filed by former soldier Rina Gonoi, whose testimony has sparked a rare public reckoning over sexual assault in Japan.

Gonoi, 23, says she was harassed by multiple male colleagues during her time in the Ground Self-Defense Force.