A few days earlier, the Iranian-Norwegian suspect had been observed photographing and watching the Danish home of the ASMLA leader, police said.
In November 2017, Ahmad Mola Nissi, an Iranian exile who established ASMLA, was shot dead in the Netherlands.
In addition, the ASMLA leader in the Netherlands was killed 12 months ago.
Andersen said that Norway had since extradited to Denmark a Norwegian national of Iranian descent who was seen taking pictures of a the Danish home of an ASMLA leader.
ASMLA strives for independence of Iran's south-eastern oil-rich province of Khuzestan that is home to Iran's ethnic Arab community and borders on Iraq at the head of the Gulf.
The Danish plot followed the killing by unidentified gunmen in the Netherlands in November 2017 of Ahmad Mola Nissi, another ASMLA leader .
The analysts note that ASMLA
operatives have maintained contacts with rebels fighting Syria's Al Assad regime.
Iran's state-run Press TV has broadcast confessions of captured ASMLA members who said they had carried out scores of attacks.
ASMLA operatives have maintained contacts with rebels fighting the Iranian-backed regime of Syrian President Bashar Al-Assad.