The Weeknd has been the "biggest support" to Selena Gomez in her recovery after undergoing a kidney transplant.

The Weeknd and Selena Gomez

The Weeknd and Selena Gomez

The 25-year-old singer revealed earlier this week she had to undergo the serious operation as a result of her ongoing battle with autoimmune disease Lupus, and sources have now claimed her boyfriend - whose real name is Abel Tesfaye - has been instrumental in her long road to recovery.

An insider said: "Abel has been one of her biggest supports. She had been traveling with him on his tour and he was off during her surgery and right after during her recovery. He's been very caring and it's meant a lot to her to have him by her side."

And the 'Fetish' singer has also received support from her "close group" of friends.

The insider added to People magazine: "She was feeling really lethargic and worn out before the surgery. The surgery was a couple months ago so she's been recovering and is in a much healthier place now. Her close group of girlfriends have all been there for her."

Meanwhile, Selena revealed the details of her kidney transplant in a lengthy Instagram post on Thursday (14.09.17), in which she claimed her recovery was the reason she laid low over the summer.

She wrote: "I'm very aware some of my fans had noticed I was laying low for part of the summer and questioning why I wasn't promoting my new music, which I was extremely proud of. So I found out I needed to get a kidney transplant due to my Lupus and was recovering. It was what I needed to do for my overall health. I honestly look forward to sharing with you, soon my journey through these past several months as I have always wanted to do with you. "Until then I want to publicly thank my family and incredible team of doctors for everything they have done for me prior to and post-surgery. And finally, there aren't words to describe how I can possibly thank my beautiful friend Francia Raisa. She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis. Lupus continues to be very misunderstood but progress is being made. For more information regarding Lupus please go to the Lupus Research Alliance website: www.lupusresearch.org/ (sic)"