The kingdom has been the focal point of the outbreak of the virus, known as the Middle East Respiratory Syndrome.
Iran's Hamshahri daily today quoted health ministry official Mohammad Mahdi Gouya as saying the virus was confirmed in two sisters in Kerman in southeastern Iran. One was reported to be in critical condition.
Gouya says there are also two other suspected cases, from the same family as the sisters.
About 600 people have had the illness and about 175 people have died.