Muhammad Ali has been placed on life support and doctors have warned his family "the end is near".

Four of Ali's nine children, including Laila, Hana, Maryum, are at the hospital in the Phoenix area. The boxing legend has been fighting a breathing problem. Doctors have told the family the chances of the 74-year-old surviving are "uncertain".

Doctors were discussing whether to transport him to another area of the hospital, but it was called off as any move could be deadly.

Ali's breathing problem has reportedly been complicated by his Parkinson's disease.

“Like in the ring, Ali is a fighter on the ward,” said a source. “Doctors are working to regulate his breathing put it is being hampered by his Parkinson’s. His children are all extremely concerned and dropped everything to be with him. They fear the worst."

We'll keep you up to date on this story as more information becomes available.