A spokesman for the Iranian embassy in Baku, Majid Faizullai, said customs officers in Azerbaijan had not detained any equipment being transported from Russia to Iran's southwestern city of Bushehr.
Earlier this week, media reported a second Russian cargo seizure by Azerbaijani authorities.
In late March, a column of vehicles carrying heat insulators for the Bushehr nuclear power plant, which the Russian contractor, Atomstroyexport, is building in the southwest of Iran, was stopped at the Azerbaijan-Iranian border.
Atomstroyexport said the shipment was registered in line with all accepted international regulations. However, Azerbaijani authorities said they had not received the information about the cargo from Russia in a timely and appropriate manner.
The cargo was finally delivered to Iran in early May. Azerbaijan said the one-month delay was caused by technical formalities rather than political issues.
Iran is currently under three sets of UN sanctions over its uranium program. The latest resolution against Iran froze accounts of certain Iranian companies and banks, and introduced inspections for goods leaving and entering the Islamic Republic.
Russia delivered its final and eighth fuel shipment to Bushehr on January 28. Russia has supplied a total of 82 metric tons of low-enriched uranium to the light-water nuclear reactor. Iran hopes its first nuclear power plant will be launched in October.