Iran has executed German-Iranian dissident Jamshid Sharmahd, following his conviction for "leading terror operations", state media is reporting.
Sharmahd was sentenced to death last year for "corruption on Earth", having been accused of leading a US-based pro-monarchist group.
He had denied the charges, with his family maintaining he was only a spokesman.
Germany's foreign minister said Berlin had repeatedly warned Tehran the execution of a German citizen would "have serious consequences".
"The killing of Jamshid Sharmahd shows what kind of inhumane regime rules (in Iran)," Annalena Baerbock posted on X.
Human rights organisations have condemned the execution of Sharmahd, who lived in the US.
"The entire process, including his arrest, conviction, and execution, constitutes a serious violation of international law," said Mahmood Amiry-Moghaddam, director of the Norway-based Iran Human Rights group.
Sharmahd is believed to have been kidnapped by Iranian agents in Dubai in 2020 and then forcibly taken to Iran via Oman.
In August 2020, Iran's intelligence ministry announced his arrest following a "complex operation", without providing any details.
Another human rights group, Amnesty International, has claimed Sharmahd was forced to confess and that he had told his family he had been tortured in detention.
It said Sharmahd had created a website to publish statements from the Kingdom Assembly of Iran, including claims of explosions inside Iran.
The little-known US-based group, also known as Tondar (Persian for Thunder), seeks to restore the monarchy overthrown in the 1979 Islamic Revolution.
However, Iranian authorities said he was Tondar's leader and had "planned 23 terror attacks", of which "five were successful", including the 2008 bombing of a mosque in Shiraz in that killed 14 people.
They published a video in which he appeared blindfolded and confessed to various crimes.
Sharmahd was sentenced to death in February last year.
'Message of terror'
Sharmahd's daughter, Gazelle, later called on German prosecutors to investigate the Iranian judiciary's alleged mistreatment of her father.
"They're killing him softly in solitary confinement in this death cell," she told the BBC in July 2023, after he had been allowed to call his family for the first time in two years.
But she added: "They want a public execution for my dad, to send out this message of terror: that anybody who speaks out against the regime, we can do this to you."
He was executed on Sunday, after approval from the Supreme Court, the Iranian judiciary's Mizan website said on Monday.
German Chancellor Olaf Scholz called the execution a "scandal" and said that "Jamshid Sharmahd did not even receive the opportunity to defend himself against the charges at the trial".