Iran's judiciary on Sunday confirmed a death sentence for a Swedish-Iranian dissident for "terrorism" over two years since his disappearance at an airport in Turkey, the judiciary's Mizan Online website reported.

Habib Chaab has been held in Iran since October 2020 after he vanished during a visit to Turkey and was put on trial in Tehran -- which does not recognise dual nationality.

Chaab, who was found guilty on charges of "corruption on earth" and the formation of a rebel group, was sentenced to death on December 6.

On Sunday, it was confirmed that Iran's Supreme Court had upheld the ruling.

"The death sentence of Habib Farajollah Chaab on charges of corruption on earth through the formation, management and leadership of a rebel group called Harakat al-Nidal, and the design and execution of numerous terrorist operations in Khuzestan province, was approved by the Supreme Court," Mizan Online reported.

Iran has accused Harakat al-Nidal of "cooperation with other terrorist groups" including in a 2018 attack on a military parade in Ahvaz in the southwestern Khuzestan region that authorities said killed 25 and wounded almost 250.

Chaab is the latest person to be sentenced to death after being found guilty for being members of Harakat al-Nidal, which Tehran calls a "terrorist group".

Last week, a court in Ahvaz sentenced to death six men over attacks who had "carried out the orders of their European leaders".

They were found guilty of "armed operations" between 2017 and 2019 that killed four people, including a soldier and two members of Iran's Basij paramilitary force, the report said.

The Islamic Republic of Iran executes more people every year than any other nation except China, according to rights groups including Amnesty International.

Last month, Iran's judiciary put to death a Kurdish militant who had been convicted of killing a police officer, a move condemned by rights groups who called him a political prisoner.