Retired archbishop Desmond Tutu has been admitted to a South African hospital for the third time in recent months.
Mr Tutu's daughter Mpho Tutu said her father was taken to hospital on Monday evening.
He is being treated for inflammation, she said, adding that it is not the same infection that Mr Tutu had been treated for earlier.
Mpho Tutu added that doctors anticipate her father will be home from hospital within a few days.
Mr Tutu, 83, was admitted to hospital on July 28 for a week after a stay in hospital earlier in July.
The Nobel Peace Prize laureate has been treated for prostate cancer for many years.
Mpho Tutu said the cancer is under control.
"He is in good spirits. It's the right place for him to be right now," said Mpho Tutu.
"As you know, and as my father is finding out, he is 83, not 38, so bouncing back from an illness is not quite as easy as it once was ... this is caution, not crisis ... we are concerned but not panicked."