Frank Bruno has admitted he was ‘knocked out’ by pneumonia but that he is recovering from the illness.
The former world champion was treated in hospital last week but is now back at home.
Bruno, 57, wrote on Twitter: “Good Morning. Thank you for all the well wishes I’ve been reading them all. I feel like I’m finally starting to mend.
“I’ve certainly never felt so ill. Pneumonia… you’ve been a knockout!”
Bruno, one of Britain’s most popular sportsmen, won the WBC heavyweight title at the fourth attempt when he beat American Oliver McCall at Wembley in September 1995.
He had previously lost title bouts to Tim Witherspoon, in 1986, Mike Tyson in 1989 and Lennox Lewis in 1993.
Last week marked the 30th anniversary of Bruno’s most famous fight, when he took on the fearsome Tyson at his peak.
Then aged 27, Bruno rocked the American champion with a left hook in the early stages, only for Tyson to recover and win in the fifth round.
Bruno’s final professional bout was a third-round defeat by Tyson in March 1996, the first defence of his world title.
A regular ringside spectator, Bruno was pictured looking fit and healthy at the fight between Chris Eubank Jr and James Degale on February 23.
It is understood Bruno was taken ill over the weekend after an event hosted by comedian Jed Stone in Harrogate on Saturday night.
The 57-year-old has been treated at The Horton General Hospital in Banbury and now faces a “few weeks” of rest in order to make a full recovery.