The body of the king, who ruled England from 1483-85, was discovered last year by archaeologists at the University of Leicester, and scientists have since been undertaking careful analysis of the remains.
A team of researchers led by Dr Piers Mitchell, of the Department of Archaeology and Anthropology at Cambridge University, used a powerful microscope to examine soil samples taken from the skeleton's pelvis and skull, as well as from the soil surrounding the grave.
It revealed multiple roundworm eggs in the soil sample taken from the pelvis, where the intestines would have been situated, The Guardian reported.
Roundworms infect humans when people ingest their eggs via contaminated food, water, or soil.
Once eaten, the eggs hatch into larvae, which migrate through the tissues of the body to the lungs where they mature.
They then crawl up the airways to the throat to be swallowed back into the intestines, where they can grow into adults around a foot long.
It is spread by the faecal contamination of food by dirty hands, or use of faeces as a crop fertiliser.
"Our results show that Richard was infected with roundworms in his intestines, although no other species of intestinal parasite were present in the samples we studied," Mitchell was quoted as saying by the paper.
"We would expect nobles of this period to have eaten meats such as beef, pork and fish regularly, but there was no evidence for the eggs of the beef, pork or fish tapeworm. This may suggest that his food was cooked thoroughly, which would have prevented the transmission of these parasites," he said.
His body was buried in Greyfriars Church in Leicester. His remains were excavated from under a council car park, the former site of the church, last September.
