The superstar first met Chelsea James while on tour in Sydney in 2009, when she invited the then-11 year old up onstage so she could serenade her with her hit song Halo.

Beyonce organised a second meeting with young Chelsea when her Mrs. Carter Show World Tour headed Down Under in 2013, and promised to visit her every time she returned to Australia.

However, the teenager's health took a turn for the worse just four months later in early 2014, and when Beyonce learned Chelsea had been given just two weeks to live, she set up a time and date to call the young fan on her cell phone so they could enjoy one last conversation together.

Chelsea, who had battled the disease for a decade, died in April, 2014, and Beyonce paid her respects by sending 100 white roses to her funeral in Newcastle, New South Wales, along with a sweet note addressed to her grieving mum, Donna.

The message read: "Donna, love and prayers to you and your family. Chelsea was a beautiful girl and I am so happy I was able to meet her. She touched my heart and I will never forget her.''

The news of the secret phone call was only made public on Monday (02Nov15), when Gary Nunn, who previously worked with children's cancer charity Camp Quality, which helped to reconnect the pair, penned a piece about the bond Beyonce shared with Chelsea for Vogue Australia's website.

In the article, he writes, "On that special phone call, nobody knows what was said. It was an intimate moment between two women. Chelsea's mum texted me afterwards saying, 'You've made one of Chelsea's last days with us one of her happiest. Thank you - and keep being you.'

"Just under two weeks later, Beyonce sent one hundred white roses to Chelsea's funeral in Newcastle. 'Can we do anything else for the family?' Beyonce's manager asked me. 'Just ask them never to forget Chelsea,' her mum told me. It's clear she truly won't."