Bribery claims around the death sentences of Myuran Sukumaran and Andrew Chan must be investigated urgently as the pair await their execution within days, their lawyer is arguing.

Muhammad Rifan, the lawyer who represented the Bali Nine pair when they were sentenced to death in 2006, has told Fairfax Media judges asked for more than $130,000 for a lighter sentence.

Mr Rifan raised the claims months ago - without putting a sum on the bribe - and the men's current lawyer, Todung Mulya Lubis, has already lodged a complaint with the judicial commission, which appears to have stalled.

Mr Lubis says the commission has an obligation to finish its probe and it's not too late to stop the firing squad, which is set for Tuesday.

"We appeal to the attorney-general, we appeal to the president in the name of due process of law, in the name of fairness and justice, not to do the executions," he said.

"This is not an act of (a) desperado, this is a demand for justice."

Mr Lubis says claims the men face execution because of a corrupt system must be urgently investigated.

"I know that we are counting the hours," Mr Lubis told reporters at Cilacap before visiting the Australians.

"I know that we've done everything possible under our legal systems.

"But Sukumaran and Chan still feel there's something wrong with all these legal proceedings, especially at the district court in Bali."

The pair also have a constitutional court challenge lodged, which would require clarity around the president's obligations on answering clemency requests.

The case is set down for a preliminary hearing on May 12.

Amid the last minute pleas, the Chan and Sukumaran families took a boat from Cilacap to the island of Nusakambangan on Monday morning for some of their last hours with their loved ones.

They initially left the Cilicap port followed by Australia's consul-general to Bali, Majell Hind, and lawyer Julian McMahon after it was believed they were told the visitation rules had changed.

They later returned to the port and were allowed passage to Nusakambangan, where the men will be executed.

Foreign Minister Julie Bishop says she's disappointed Indonesia ignored Australian government requests to delay the execution notices until after Anzac Day.

Despite the representations, Jakarta handed the pair their notices on Australia's "national day of remembrance", Ms Bishop said.

Meanwhile, Prime Minister Tony Abbott is due to meet French President Francois Hollande in Paris on Monday where they'll discuss the executions of 10 prisoners.
Mr Hollande shares Australia's concerns about the executions.

Frenchman Serge Atlaoui has been given a reprieve pending an appeals process, which followed strong diplomatic efforts by France.