Three-time former heavyweight boxing champion Muhammad Ali was readmitted to the hospital on Thursday for follow-up care related to a severe urinary tract infection, The New York Times reported.

There were reports that Ali, who turns 73 on Saturday, was rushed to the hospital unresponsive. But a spokesman for Ali said the claims were untrue, according to the Times.

Ali had been hospitalised on Dec 20 for the same infection. It is his second time in the hospital in the past month.

But he is expected to be released on Friday, his spokesman told the Times.