An expert witness has argued for the death row challenge of Andrew Chan and Myuran Sukumaran to be heard in an Indonesian administrative court, testifying it is the correct forum.

The court last month threw out a challenge against the rejection of clemency for the Bali Nine pair, determining the decrees by President Joko Widodo were not within its jurisdiction.

The men sentenced for heroin smuggling in 2006 have no other legal avenues left and have resorted to the administrative court appeal to spare them from the firing squad.

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Otong Rosadi of Ekasakti University on Monday gave his opinion in support of the challenge.

The law expert said in his opinion, all “products of the law” can be reviewed, even clemency, which he argued was not purely a matter of presidential prerogative.

The constitutional rights of the president were still a product of the law, he said.

“The legal product is the presidential decree and a presidential decree rejecting or granting clemency, it’s a state administrative matter,” he told the court in Jakarta.

“The forum to challenge it is the state administrative court.”

Mr Otong maintained this view under questioning from lawyers for the state and judges, who asked if other constitutional rights of the president could also therefore be challenged in the administrative court.

Lawyer for Chan and Sukumaran, Leonard Arpan, said he was confident Mr Otong’s evidence was strong.

“I think the expert has delivered all the statements that were required,” he said.

Both sides are due to give their conclusions on Wednesday for a decision soon afterwards.

If they are given the chance, lawyers for Chan and Sukumaran will argue President Joko Widodo didn’t properly assess their case – including their rehabilitation – before refusing clemency because they are drug offenders.

Several of the 10 prisoners in line for Indonesia’s planned simultaneous mass execution are pursuing court action.

Indonesia’s Attorney-General HM Prasetyo has committed not to execute them before their legal avenues are exhausted, and has ordered those cases before the Supreme Court to be expedited.

The tenth prisoner, Filipina Mary Jane Fiesta Veloso, will soon join the others on Nusakambangan island as her bid for a Supreme Court judicial review was rejected last week after a matter of days.

– AAP