Anthony Riley, a Philadelphia street performer who earned national notoriety as a contestant on "The Voice," has died of an apparent suicide. He was 28.

Deadline Saturday confirmed his death, noting Riley walked away from "The Voice" this past season to seek treatment for substance abuse. said his body was found Friday in the basement of the Center City apartment where he was staying.

The manner in which he died was not immediately disclosed.

"He'd had his problems recently. But at the heart of all that was a very kind, gentle person," his friend and fellow musician Robby Parsons told

Travis Ewing, who competed against Riley on "The Voice," expressed on Twitter his sorrow over Riley's death.

"Tough day for The Voice fam. Anthony was my battle round partner and a close friend on the show. He will be missed," Ewing tweeted.