Under Iran's Islamic law, adultery is punishable by stoning, but such sentences are rare. International human rights groups have long criticized stoning in Iran as a cruel form of punishment.
Jamshidi did not describe how the stonings were carried out. But typically under Islamic rulings, a man is buried up to his waist, while a woman is buried up to her neck. Those carrying out the verdict then throw stones until the person dies. If the person manages to escape from the hole, he or she will remain free under Islamic law.
"Given that the third person managed to pull himself out of the hole, the verdict was not carried out," Jamshidi told reporters.
Stonings were widely carried out in the early years after the 1979 Islamic revolution that toppled the pro-Western government and brought hardline clerics to power. But in recent years, it has seldom been applied, although the government rarely confirms when it carries out stoning sentences.
The last time Iran reported a death by stoning was in July 2007 when Jamshidi said a man convicted of adultery was stoned to death in a village in northern Iran.
Women's rights activists headed by feminist lawyer Shadi Sadr have been campaigning to have the sentence removed from Iran's statutes.
Iran's reformist legislators have demanded an end to death by stoning as a punishment for adultery, but opposition from hardline clerics has sidelined their efforts.