Tito Jackson has died aged 70, according to family friend and former manager Steve Manning.
The Jacksons star is said to have suffered a heart attack while driving from New Mexico to Oklahoma, with the Jackson family's former manager Steve Manning confirming the sad news to ET.
An official cause of death is not known.
The iconic group – also comprising Tito's brothers Marlon, 67, and Jackie, 73, and his son Taryll, 49 - had played several shows this year, with Tito last onstage in Munich, Germany on September 10.
The older brother of the late King of Pop Michael Jackson and sister Janet, 58, shot to fame alongside his siblings in the Jackson 5 - who would later become the Jacksons - in the late 1960s and 1970s under the legendary Motown label.
The original line-up consisted of Jackie, Tito, Marlon, Michael, and Jermaine Jackson, 69.
Their best-known hits included “ABC”, “The Love You Save”, and “I'll Be There”.
Tito was inducted into the Rock and Roll Hall of Fame as a member of the Jackson 5, and the Jacksons received a star on The Hollywood Walk of Fame in 1980.
The singer and guitarist also embarked on a solo career in 2003 as a blues musician.
Just a few weeks ago, Tito spoke about still feeling the "feel the presence" of his brother Michael.
The 70-year-old singer discussed the "tragedy" of the “Thriller” hitmaker's passing from Acute propofol intoxication 15 years ago, aged 50, and admitted the world "missed out on a lot of goodness" from the music legend.
Tito said of his scandal-hit sibling: “The world was not kind to Michael at all. I don’t know why. I would always say if we didn’t have him, we sure would miss him. His death was such a major tragedy.
“The world definitely missed out on a lot of goodness from him, because he wasn’t just a musician or an artist, he was a loving person. He loved to give.”
Discussing where he believes the “Beat It” hitmaker would be now, he said: “We always feel his presence on the stage. So that helps us a lot too.
“I can imagine Michael probably would have had three or four more hits by now, and they’d still be talking about him on the radio.
“When that time of year comes around, you feel this presence and just try to enjoy all the moments that you remember that you had together.
“Sometimes we like to have a performance on that day. Those are the days I really feel close to him, when we’re working and enjoying music, because that’s what we did together. Besides being brothers, that was our play time.”
Bang Showbiz