Reza Pahlavi, the Iranian opposition figure and son of the last shah, received a "Freedom Prize" in Frankfurt, Germany, on Saturday. The Friedrich Naumann Foundation, which is tied to the pro-business Free Democratic Party (FDP), presented the award at St Paul's Church.
Police said about 18,000 people rallied in support of Pahlavi. Factions within the Iranian opposition have accused him of failing to distance himself from his father's rule. The shah was deposed in the 1979 revolution, which led to the creation of an Islamic republic.
In his speech, Pahlavi said Iran "is a country not waiting to be taught democracy, this is a country being prevented from practicing it." He said he accepted the prize only as a "trustee" until a democratically elected government takes power in Iran. "One day I will place it in the hands of its rightful owners, not on foreign soil but in the capital, Tehran," he said. The crowd chanted "Long live the shah, long live Iran!"
Rights groups say thousands were killed in a government crackdown on protests in January, according to the report.
Around 200 prisoners held in Iran signed a letter protesting the award, according to Sahar Sanaie, spokeswoman for the Society for German-Iranians in Hesse, as cited by AFP. The letter described Pahlavi as a symbol of a "bygone dictatorship."
The Frankfurt branches of the Social Democrats (SPD) and the Greens boycotted the event, saying he cannot be considered a legitimate representative of the Iranian people. The Left Party argued that the church should not have hosted the event because Frankfurt city statutes bar the use of places of worship for political gatherings.