Grand Mufti Sheikh Abdul Aziz al-Sheikh told the Saudi-controlled regional daily that making false claims about the hajj only confuses pilgrims and is sinful.
"Those who want to use the pilgrimage and spread falsehoods and propaganda for their personal goals and needs, doing this to take advantage of the occasion, are doing something forbidden by Islam," he told the newspaper.
Earlier this month, Iranian President Mahmud Ahmadinejad and Supreme Leader Ayatollah Ali Khamenei alleged that Saudi Arabia, a predominantly Sunni Muslim country, might abuse the mainly Shiite Muslim pilgrims from Iran during the hajj, which begins in mid-November.
On Monday, Ahmadinejad warned that Tehran would "take the appropriate measures" if Iranian pilgrims are restricted, while Khamenei raised the issue of alleged "insults and mistreatment against some Shiite Muslims," saying "the Saudi government must take action against such acts."
After those remarks, Saudi Hajj Minister Fuad al-Farsi said Iran "should not take advantage of the pilgrimage for political purposes and its own agenda."
Regional rivals Saudi Arabia and Iran are regularly at odds over Iran's claims of mistreatment of Shiite pilgrims to Mecca.
Several times during the 1980s, Iranian pilgrims mounted demonstrations in the holy city in western Saudi Arabia, and in 1987 Iranian pilgrims rioted, leading to more than 400 deaths.
The pilgrimage to Mecca is one of the five pillars of Islam, which the Koran holds as a once-in-a-lifetime obligation for every able bodied Muslim who can afford it.