Kanye West and Kim Kardashian attend funeral for cousin's one-year-old baby Avery Anderson

Rapper Kanye West and his Keeping Up With The Kardashians star wife Kim Kardashian were among the mourners at his cousin's infant son's funeral.

Avery Anderson died in his sleep a week ago, aged just 17 months, after showing no previous signs of illness.

The tot's father Ricky Anderson – who is Kanye's cousin on his late mother Donda's side – revealed the devastating news on social media.

Uploading a black and white photo to Instagram, he wrote alongside it: "Today was the worst day of my life!! I lost my lil man and gained an angel! Rest in Paradise!!!! I love you man."

Music executive Anderson has since shared a series of clips with similarly heart-breaking captions.

After saying goodbye to his son for the last time, he posted a video showing the curly haired lad sitting with a dog and looking happy.

He captioned it: "I love you Ave!! You are on my heart everyday!! Thank you all who celebrated his life today!"

Avery's mother Erica Paige also paid an emotional tribute online to her boy who had only turned one in October.

She wrote: "This life in so unfair. I love you with everything inside me and it is with incredible, unbearable pain that I will have to try to find the strength to do a single thing without you.

"I am so grateful for being able to spend almost 17 months with you. You brought me so much happiness and I'm so proud of how hard you fought.

"Thank you for all the laughs, cuddles, hugs and kisses, you took care of me in a way no one else could. My heart is forever broken. I love you so much, mommy is with you."

While neither Kim or Kanye – who are parents to three-year-old daughter North and one-year-old son Saint – have made mention of Avery's passing online, both looked sombre as they attended the service with friends and family in Los Angeles.

Kim, 36, opted for an ankle-length black dress, a fur overcoat, and a pair of oversized black sunglasses with her long black hair loose down her back.

Kanye, 39, wore an all-black suit and large amber shades for the funeral on Friday (March 24).