The Canadian artist and model was found dead at his home in Montreal. After hearing the news, Gaga announced Genest's death on Twitter and said it was "beyond devastating".
"We have to work harder to change the culture, bring mental health to the forefront and erase the stigma that we can't talk about it," she added.
However, the pop star has since deleted those tweets and issued an apology where she suggests she "spoke too soon", after Genest's manager Karim Leduc speculated that he had fallen from the balcony by accident as he was smoking on a fire escape.
"The balcony from which he fell on the third floor was a very dangerous balcony," Leduc said.
"Just three weeks ago, I visited that balcony with him and was on it smoking a cigarette as well. It's a balcony that has very small rails/guards - an emergency/fire escape balcony - and he was leaning his back towards it, like sitting on the ledge of the rail, and he fell onto the floor."
Born and raised in Montreal, Genest got his first tattoo when he was 16, and had his entire body covered in ink around three years later, with the corpse-themed body art leading to his monker "Zombie Boy". He starred in Lady Gaga's video for "Born This Way" in 2011.
"Out of respect for Rick's family, Rick & his legacy I apologise if I spoke too soon as there were no witnesses or evidence to support any conclusion for the cause of his death," Gaga posted in a new tweet. "I in no way meant to draw an unjust conclusion... my deepest condolences to his entire family and friends."
Radio-Canada cited police sources as saying it appeared to be a suicide. An official cause of death has not yet been announced.
If you or someone you know is struggling with mental health, you can call the Samaritans confidentially on 116 123 or visit mind.org.uk
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