Martin's longtime friend, Lisa Lenes, said the Buffalo Springfield drummer's death Sunday was likely of natural causes, although no official cause of death had been determined, the Los Angeles Times reported Friday.
Martin performed in the rock band alongside Neil Young and Stephen Stills during its two-year existence, during which time the band created three studio albums.
While tensions between band members ultimately prompted the band's dissolution, Young had nothing but praise for Martin in his autobiography "Shakey."
"You get harder, he hits harder. You pull back, he hits back," Young said of Martin. "He can feel the music -- you don't have to tell him."
The Times said Martin, who leaves no reported survivors, was inducted into the Rock and Roll Hall of Fame along with his fellow Buffalo Springfield members in 1997.