The details were added after the first paragraph (the first version was posted at 08:18)
A Spanish consul in Tehran was detained by Iranian special services for a certain period on Feb. 14, dpa reported with reference to Spanish media as saying.
Advisor for consular affairs Ingacio Perez Cambra was apprehended by several plain-clothes officers Monday outside the Spanish embassy where he worked.
The 42-year-old diplomat was held in a police station for foreigners for four and a half hours before he was released, dpa reported.
According the online edition of daily El Pais, the consul was out for a walk with the Spanish ambassador at the same time as anti-government demonstrators went ahead with a planned protest despite warnings from the authorities.
The Foreign Affairs Ministry has summoned Iranian Ambassador Madrid Morteza Saffari Natanzi, and Foreign Minster Trinidad Jimenez sent a note of verbal protest to the Iranian authorities, calling the incident "inacceptable" and "very serious," the reports said.
Spain has also called off an upcoming visit by a senior official of the Iranian Foreign Ministry.