Madonna said Thursday she has had the coronavirus and that it was why she had to cancel a concert in Paris in February, though she is not currently sick.
The "Queen of Pop" said she had tested positive for antibodies which may mean she had has COVID-19.
"I am not currently sick," she told her 15 million followers on Instagram.
"When you test positive for anti-bodies it means you had the virus, which I clearly did as I was sick at the end of my tour in Paris over seven weeks ago along with many other artists in my show," she said.
The 61-year-old star only played a single night at the Grand Rex on February 22 before calling off the next show, citing "ongoing injuries".
She later called off two further Paris concerts -- the last in her Madame X world tour -- after French authorities banned large gatherings in a bid to stem the spread of the virus in early March.
"At the time we all thought we had a bad flu," Madonna wrote in her post.
"Thank God we are all healthy and well now," she added.
Scientists are sceptical about the accuracy of many antibody tests which claim to show a person has had virus.
Some warned that even those tests that meet the US government's informal standards may produce false positives.
The singer revealed she had the virus after sharing an article about her donating $1.1 million (one million euros) towards research to find a vaccine for the coronavirus.
