This is the heartwarming moment a young boy stunned shoppers with his incredible voice after unexpectedly breaking into song.

Calum Courtney, 10, wowed supermarket crowds with his impressive rendition of Smokey Robinson's Who's Lovin' You.

The youngster has a mild form of autism, which inspires him to sing and help others.

And the performance has piqued the interest of a producer and writer who wants to write a charity single with him in the New Year.

Mum Tupney Courtney, 34, said: "He loves how it feels and hearing the sound of his voice when he sings.

"He is always singing around the house and performing in public has never been a problem. The more people, the better for Calum when he is performing.

"He did not realise how good he was until he saw the video, he said: 'Mum, I'm actually really good.'"

Ms Courtney says her son 'is always singing' Courtney family/SWNS (Courtney family/SWNS)

A video of Calum's performance in Basildon, Essex, has been seen over a million times on YouTube and has been shared more than 12,000 times.

But mum Tupney revealed that the video was originally only supposed to be seen by his dad, before her sister Katy posted it on Facebook.

She said: "I do not think people thought that it was Calum singing at first and it was just the music in the shop.

"I decided to video it for my husband because he was at work, then my sister put it up on Facebook.

"Calum has high functioning autism. For Calum this means blurred social boundaries, struggles with school and difficulties with friendships, but also that enables him to have no fear to get up and belt out a song.

"We describe his autism to him as a superpower, it may take a little from other areas of life but it’s given him the superpower of music."

Calum has shared stages with some of the UK's most popular artists Courtney family/SWNS (Courtney family/SWNS.COM)

The schoolboy is no stranger to singing in aid of charities, having previously sung on the same stage as Emile Sandé and JP Cooper at the NSPCC Winter Charity Ball in aid of the National Autistic Society.

Tupney added: "He has no nerves, if there's an audience, if there's anybody from one to 100 people to sing in front of he loves it, he just loves to sing.

"He taught himself to play the drums when he was 18 months old and he's just incredible with music, it's in his blood.

"Both my parents were on the West End and he takes after that."

The young boy learnt to play the drums as a toddler Courtney family/SWNS (Courtney family/SWNS)

Calum, from Basildon, Essex, will be in the studio in the first week of January where he hopes to record his first charity single.

She said: "The only way he will know if he wants to do it as a career is if he tries it because it is not easy.

"He thinks he's gonna be able to buy a mansion, he has a bit of an obsession with building them on Minecraft."