Ricky Hatton will undergo tests over the next few days after being admitted to hospital in Manchester suffering from stomach cramps and vomiting.
The 30-year-old former light-welterweight world champion complained of feeling unwell on Monday and was taken to Tameside General Hospital yesterday morning.
His agent Paul Speak told the Daily Express: "He has been feeling unwell for a couple of days and overnight he could not sleep.
"His girlfriend Jennifer took him to hospital at about 8am as he was vomiting and suffering stomach cramps.
"Initially we thought it was just a bug and he would get over it, but it was definitely getting worse.
"He will be in for tests for a few days to determine exactly what Ricky has caught, but we can confirm it is definitely not swine flu."