Finn Borch Andersen, head of the Danish intelligence agency Pet, said the arrested Norwegian citizen had denied charges in court of helping a foreign intelligence service plot an assassination in Denmark.
Andersen said the suspect had taken photographs of the residences of members ASMLA, which Iran considers a terrorist organization.
A Norwegian citizen of Iranian background was arrested in Sweden on October 21 in connection with the plot and extradited to Denmark, Swedish security police said.
Foreign Minister Anders Samuelsen also summoned the ambassador of Iran, Morteza Moradian, to a meeting. "The government will give the answer of Iran and is discussing with our European partners further actions", - he wrote on Twitter.
This article has been adapted from its original source.
The group has been named by Tehran as being behind a terror attack on a military parade in the city of Ahvaz on September 22 that left at least 25 people dead.
Foreign Ministry spokesperson, Bahram Ghasemi, said the allegations were a "plot" against "growing Iran-Europe relations", Iran's Mehr News quoted him as saying. Apart from the move, the minister stated that the Danish side would push for more EU-wide sanctions against Iran. ASMLA condemned the violence and said it was not involved.
It is totally unacceptable that Iran or any other foreign state plans assassinations on Danish soil. Following the deadly assault in Ahvaz, the Iranian regime accused Denmark, the Netherlands and Britain of "hosting several members of the terrorist group". It is likely that any sanctions the European Union might impose would not violate the Iranian nuclear deal but instead target the country's intelligence apparatus.
During a televised press conference, Borch Andersen noted that Iran already was suspected of targeting opposition groups overseas.
"For almost 40 years, Europe has been the target of #Iran-sponsored terrorist attacks".
An Iranian diplomat was among six people who were arrested for allegedly plotting the bombing of the event, which featured among its guests senior U.S. politicians including Rudy Giuliani, Donald Trump's attorney. "We call on our allies and partners to confront the full range of Iran's threats to peace and security".
Tehran has alleged the group was responsible for an attack in September on a parade in the city of Ahvaz, in which at least 25 people were killed and 60 others injured.
Four people were arrested in connection with an Iranian-led bomb plot against an Iranian opposition group in Paris this past summer.