Dion's rep confirmed to ET on Friday that the 47-year-old singer's older brother, Daniel Dion, is fighting a serious battle with cancer. Dion's husband, René Angélil, died on Thursday after his own long battle with throat cancer.
Daniel, 59, is one of Celine's 13 brothers and sisters. According to a recent interview Celine's sister, Claudette, gave to The Journal of Montreal, Daniel only has "a matter of days or hours" to live.
"It looks a lot like René, he had cancer of the throat, tongue and brain," Claudette said of her brother's condition. "Our family is very experienced."
"He is 59 years old, very young to be the end of life," she added.
Claudette said part of the Dion family -- including Celine's 88-year-old mother, Therese Dion -- were gathered at Daniel's beside on Thursday, after they were informed that Daniel was "dying."
"We are with Daniel, day and night," she said.
Celine has already canceled her upcoming Las Vegas shows on Jan. 16 and Jan. 17 following René's death.
"We are heartbroken to hear this news, not only because René was a great friend and mentor and an extraordinary partner with us in these shows at Caesars Palace for the last 13 years, but even more because he and Celine were so devoted to each other; their relationship has been a model for us all," a spokesperson for AEG said in a statement.