A heartwarming video of Michael Bublé performing on stage with his eldest son Noah has re-emerged following the tragic announcement that the three-year-old has been diagnosed with cancer.

Filmed at a party in December last year, the singer, 41, is seen performing on stage before asking the audience if he can bring a special someone on stage to do a duet with him.

Addressing the audience, the Grammy-winner says: ‘I promised someone here I would do a bit of a duet with them, and I don’t know if they’re going to do it with me…’

Michael Bublé sings with son Noah during a party in December 2015

Watch their performance below.

As the crowd guessed it would be his eldest son taking to the stage, they cheered ‘Noah!’ until Michael plucked the toddler from the audience and sat him on his knee.

As Michael launched into an acapella version of his hit, Nobody But Me, the youngster seemed shy at first, burying his head into his father’s shoulder before plucking up the courage to sing along.

Cheered on by the crowd, Michael then attempted to hand his son back, but the adorable toddler refused to let go, grasping his father for a hug.

The touching clip has been circulating social media following the sad news that Noah has been diagnosed with cancer.

In a Facebook post by the singer and his wife Luisana Lopilato, 29, the pair announced: ‘We are devastated by the recent diagnosis of cancer of our oldest son Noah, who is currently receiving treatment in the United States.

‘We’ve always talked a lot about the importance of family and the love we have for our children.’

‘We are devastated’: Michael and Luisana shared the sad news that the youngster has been diagnosed with cancer

‘My kids changed my life!’: Michael Buble on his children