TOKYO, July 19 (Reuters) - Japanese musician Keigo Oyamada has stepped down as a composer for the Tokyo 2020 opening ceremony after old reports of his bullying and abusive behaviour resurfaced, days before the pandemic-hit Olympics is due to officially start. Oyamada, who had been tasked with composing the music for the ceremony slated for July 23, has come under fire in recent weeks after past issues of the magazines began circulating online. Oyamada told Quick Japan magazine published in 1995 how he had confined a classmate in a cardboard box and made fun of a student with disabilities, the Asahi Shimbun daily reported last week. He also described bullying a classmate in another magazine published in the mid-1990s, the paper said. Some media accounts of the interviews contain references to degrading and abusive treatment, including Oyamada forcing another child or children to eat faeces or to masturbate. Reuters could not independently verify the interviews, although alleged photos of the magazine pages have circulated widely on social media. "As for my participation in the Tokyo 2020 Olympic and Paralympic Games, I acutely feel that my having accepted the request was lacking consideration for various people," Oyamada said on his Twitter page. "I made arrangements with relevant parties and submitted my resignation to the organising committee." His announcement came just hours after Tokyo 2020 organisers said they wanted Oyamada to stay on to prepare for the ceremony. Chief Cabinet Secretary Katsunobu Kato had told a regular news conference on Monday that he expected the Tokyo 2020 organisers to handle the issue adequately. In a statement on his homepage on Friday, Oyamada, also known as Cornelius, said he felt deep remorse and responsibility. "I offer my heartfelt apology ... In my school days and at the time of the (magazine) interviews, I was a very immature man who could not imagine how the victimised feel," he said in the statement. Oyamada"s resignation, which came just four days before the closely watched opening ceremony, is the latest in a series of headaches and embarrassments for the Tokyo Olympics organisers. The former Tokyo 2020 president, ex-prime minister Yoshiro Mori, stepped down in February after making sexist comments, while Tokyo Olympics creative head Hiroshi Sasaki resigned in March after making a derogatory comment about a popular Japanese female entertainer. There is widespread concern among the public over the safety of holding the international sporting event amid the coronavirus pandemic. The Games were postponed for a year due to COVID-19 outbreaks, and the number of infections in Tokyo has been on the rise again in recent weeks. read more