Judiciary spokesman Gholamhossein Esmaili did not identify the pair or give any other details about when and where they were detained.
“Two Swedish nationals were arrested by the judiciary for trafficking drugs,” which were still in their possession, he said.
“We informed their government and embassy about their arrest through the foreign ministry,” he said, quoted by the judiciary's Mizan Online website.
The spokesman said the Swedes had been informed that they “can enjoy consular services, meeting privileges and the like”.
Tasnim news agency, which is close to ultraconservatives, reported at the beginning of July that two Swedish members of an “international drug gang” had been arrested as part of a “complex operation”.
“A big part of the large shipment discovered was dangerous industrial narcotics,” it said, adding that the network had been dismantled.