Johannesburg — A South African foundation says retired archbishop Desmond Tutu has undergone a "small investigative procedure" in a hospital to assess an infection he has had for several weeks.

The foundation, which is named after Tutu and his wife Leah, said Saturday that the Nobel Peace Prize laureate will remain in the hospital in Cape Town for several more days.

Tutu has been treated for prostate cancer for many years. The foundation quotes Tutu's daughter, Mpho, as saying the cancer is under control but the infection is the result of past treatment for the disease.

Mpho Tutu says doctors are satisfied with the progress of her father's antibiotic treatment.

Desmond Tutu was admitted to the hospital on July 28 after a weeklong stay there earlier in the month.