Mr Ruddock is now campaigning for the end of the death penalty around the world.

"That's what I would have said because I feel that very strongly; it's what happens in relation to extradition.”

"If they'd come to me I would have said 'Make some enquiries about the possibility of there being a death penalty'," he said.

He said he would have insisted the federal police gained assurances that the suspects would not be exposed to the death penalty before any information was handed over.

Mr Ruddock said if he had been consulted - and if the present guidelines were in place - it would have been a different story for the Bali Nine.

Former attorney-general Philip Ruddock has spoken out about the Bali Nine case following a press conference from the AFP today.

"Without that answer there can be no surety that this will not occur again," Senator Xenophon told reporters in Canberra.

He says the "largely unanswered" question is why the group was arrested in Indonesia and not Australia.

He has queried an Australian Federal Police explanation of its role in the investigation that led to the executions of ringleaders Andrew Chan and Myuran Sukumaran last week.

Federal police faced an agonising decision but they should have arrested the Bali Nine drug smugglers in Australia, independent senator Nick Xenophon has argued.