"I have never met nor spoken to Renee Zellweger," Minnelli says, before clarifying that she has no involvement in the biopic whatsoever. "I don’t know how these stories get started, but I do not approve nor sanction the upcoming film about Judy Garland in any way."
Minnelli added that "any reports to the contrary are 100% fiction."
The report the Oscar-winning actress was refuting has since been taken down.
The strongly worded post comes just days after Minnelli, 72, paid tribute to her mother with a heartfelt message celebrating Garland's birthday on Sunday, along with a video of her and her mom performing a duet of "Together (Wherever We Go)" during a TV appearance.
"Yesterday would’ve been mamas birthday.... she was taken from Lorna, Joey, and me far too soon," Minnelli wrote. "I love getting to go back and see these wonderful memories."
Garland died on June 22, 1969 -- 12 days after her birthday. She was 47. Her cause of death was ruled to be an accidental overdose of barbiturates. Minnelli was 23 at the time.
In the upcoming biopic, Zellweger, 49, plays Garland during the last year of her life, long after being a household name in a slew of starring roles in iconic films like Wizard of Oz, A Star is Born and Meet Me In St. Louis.
According to Deadline, the film will follow Garland as she prepares for her sold-out run at The Talk of the Town nightclub in the winter of 1968.
The film, which is slated to hit theaters on Nov. 30, also stars Michael Gambon as Garland's manager, Bernard Delfont, while actress Gemma-Leah Devereux plays a young Minnelli and Bella Ramsey portrays Minnelli's younger sister, Lorna Luft.