Michael Buble has reportedly pulled out of hosting next month's (Feb17) Brit Awards so he can focus on his young son's cancer battle.

The singer's three-year-old boy Noah was diagnosed with liver cancer last year (16), and his worried dad put his career on hold to care for the sick kid.

Now the 41-year-old has told Brit Awards bosses he won't be able to commit to hosting the U.K. prizegiving.

A source tells The Sun newspaper, Michael made the "difficult" call to show producers on Monday night (16Jan17).

"Out of respect for Michael the producers gave him as much time as he needed to make the decision, which they completely understood," the insider told the publication.

Brits bosses are now on the hunt for potential replacements ahead of the ceremony at London's O2 Arena on 22 February (17).

Buble's cancer-stricken son reportedly underwent surgery at the end of December (16).

The singer and his wife, Luisana Lopilato, confirmed the sad news of their tot's diagnosis in November (16), after it was first reported in the La Nacion publication in the model's native Argentina.

Luisana's sister Daniela subsequently revealed the boy is battling liver cancer and Noah began chemotherapy treatment in the U.S. in a bid to shrink the tumor.

Michael and Luisana have not commented on Noah's condition since announcing their eldest son's health crisis and asking for privacy: "At this difficult time, we ask only for your prayers and respect for our privacy," they wrote in a statement posted online in November. "We have a long journey in front of us and hope that with the support of family, friends and fans around the world, we will win this battle, God willing."

Buble also pulled out of a performance at the BBC Music Awards in London after the sad news was made public.

He is still scheduled to host the Juno Awards in his native Canada in April (17).