Shakira thinks Rihanna is the ''sexiest woman alive''.

The 'Hips Don't Lie' hitmaker collaborated with the pop star on recent track 'Can't Remember To Forget You' and described the experience as ''amazing.''

Talking about appearing in the sexy music video for the song, Shakira told Magic FM: ''The thing about Rhianna is that she is such a natural, she doesn't need a camera to be in front of her to react like she does ... she is like that every second of the day.

''In my case, I need a countdown to be sexy but she's just like that the whole time, that's her. She is without a doubt the sexiest woman alive!''

The 37-year-old singer, who has released her self-titled 10th album after taking a break from music, claims Rihanna, 26, is not only one of the best performers in the world, but she's also just ''the girl next door.''

She explained: ''She is very humble and sweet and warm and that made it super easy - the interaction between the two of us.''

Meanwhile, Shakira is also a judge on the US version of 'The Voice' and says there is ''real fun banter'' between her and fellow judges Usher and Adam Levine from Maroon 5.

She added: ''There is [also] a serious aspect to the job - mentoring the new talent and new artists. But also, hanging out with these guys, is like hanging out with 13 year old boys! - I'm the most mature one there and I'm about 16!''