Madonna's social media post about a false coronavirus story appears to have been removed from Instagram, after fans flagged it down.
The 61-year-old singer shared a video from controversial US figure Dr Stella Immanuel, which had also previously been retweeted by President Donald Trump.
In her Instagram post, Madonna described Dr Immanuel as her "hero".
The video showed a number of doctors claiming malaria drug hydroxychloroquine was a "cure" and preventative measure for COVID-19.
Dr Immanuel also claims face masks are unnecessary.
She's previously used her platform in the past to spread a catalogue of outlandish claims, including theories around alien DNA and "demon sperm".
Among her most controversial conspiracy theories was the claim that the medical condition endometriosis is caused by "sex demons".
Her YouTube channel, meanwhile, sees furious opposition to the legalisation of gay marriage and abortion.
Madonna's post, which appears to have now been deleted from her page, was blurred and covered with a false information warning.
It read "reviewed by independent fact-checkers", while a "see why" button presented a list of falsehoods.
It notes that there is no cure for COVID-19, and clarifies that hydroxichloroquine is also not a cure.
Mirror Online has reached out to Madonna's reps for comment.
Twitter was recently forced to flag US president Donald Trump's tweet after he retweeted Dr Immanuel's video.
Meanwhile, his son Donald Trump Jr was landed with a temporary Twitter suspension after he called the video a "must watch".
Twitter reasoned that the president's son had spread "misleading information".
"The tweet is in violation of our COVID-19 misinformation policy," a spokesperson confirmed. "The account will be locked until the account owner removes the tweet."
Madonna recently made headlines when she claimed the Russian government had issued her a hefty fine after a passionate LGBTQ+ rights speech.
Madge, who's well known for her advocacy, delivered a powerful speech on equality during the St Petersburg leg of a 2012 tour.
Writing on Twitter, she claimed: "I made this speech at a concert in St Petersburg 8 years ago.
"I was fined 1 million dollars by The government for supporting the Gay community."