Actress Sharon Stone has shared that her sister Kelly has Covid-19 and blamed all those not wearing masks for her infection.

The actress took to Instagram to post a photo of a solitary room with a large yellow tube being fed into it, surrounded by PPE-clad doctors, reports dailymail.co.uk.

Revealing Kelly was being treated in the room, Sharon captioned the image: "My sister Kelly, who already has lupus, now has COVID-19. This is her hospital room.

"One of you Non-Mask wearers did this. She does not have an immune system. The only place she went was the pharmacy. There is no testing in her county unless you are symptomatic, & then it's 5 day wait for results. Can YOU FACE THIS ROOM ALONE? Wear a mask! For yourself and others. Please."

It's believed Kelly is at a hospital in Miami, although she had been self-isolating in Montana with her husband.

Kelly took to Instagram herself to post a video from her hospital bed, lying in the dark, "begging" her followers "to know that this is real".

"I am gasping... for every breath!" she said in the video, uploaded on Sunday morning.

"Please do this for the people that you love: stand behind more tests, more masks. Demand everyone wear masks. You never, ever want to feel like this. I promise you!"

She got tearful and said: "I only have love. My heart is breaking for people who can't breathe!"