Samuragochi, 50, had previously claimed to be the sole author of his classical works and sound tracks for video games, such as Biohazard, despite having lost his hearing by age 35. His story resonated in Japan, where perseverance is greatly admired. But he admitted Wednesday that he did not write the powerful "Hiroshima Symphony" and other works credited to him.
His ghost composer, Takashi Niigaki, said he provided music for Samuragochi for 18 years and questioned if he was hearing impaired.
"I saw no signs that he could not hear," Niigaki said as, seemingly flustered by the limelight, he struggled to answer a barrage of questions over how Samuragochi could have managed the deception for so long.
A written statement from Samuragochi's lawyers apologized for what he called a "betrayal" of his fans and described Samuragochi as being in "too unstable an emotional state" to appear in public.
On Thursday, lawyer Kazushi Orimoto told reporters that he did believe his client was hearing impaired. Samuragochi has a certificate for his disability and is classified as having severe hearing loss.
His official biography says Samuragochi was born in Hiroshima to survivors of the 1945 atomic bomb attack and began playing music and composing at an early age. The cause of his gradual hearing loss hasn't been explained.
Nippon Columbia Co. issued a statement expressing astonishment and outrage that Samuragochi had not composed his own music. The company stopped sales of his works, while major media outlets including national broadcaster NHK apologized for having run programs featuring Samuragochi as an accomplished composer.
Niigaki said he hopes to continue composing and performing despite the brouhaha over Samuragochi's admission of having faked authorship of many works, including an arrangement, "Sonatina for Violin," that figure skater Daisuke Takahashi plans to use for his short program at the Sochi Olympics.
It was his concern over Takahashi that led him to speak out, Niigaki said, as he feared that a disclosure of the truth later might be more awkward for him.
Asked how the two worked together, Niigaki said he would compose pieces and sometimes play them for Samuragochi, who would then choose which he liked.
"The music was born of my collaboration with him," Niigaki said. "I produced all the works to the best of my ability."