"Bali Nine" drug traffickers Myuran Sukumaran and Andrew Chan could face the firing squad within days, along with others from Brazil, Nigeria, the Philippines and an Indonesian prisoner.
Australian media showed photos of crosses prepared by a mortician that will be used to mark their coffins, inscribed with the date 29.04.2015.
But Foreign Minister Julie Bishop said the death row convicts should not be shot while legal question marks remain over their cases.
"And there's also a separate investigation underway by the Indonesian Judicial Commission into claims of corruption in the original trial, and both of these processes raise questions about the integrity of the sentencing and the clemency process."
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Bishop spoke to her Indonesian counterpart Retno Marsudi last evening, while Prime Minister Tony Abbott has written to President Joko Widodo to renew his plea for the executions to be halted.
Abbott meanwhile stressed his opposition to the death penalty "in all cases" on a visit to Paris on Monday, a view echoed by French President Francois Hollande in a separate statement.
Today Fairfax Media published allegations of corruption by the judges who sentenced the pair in 2006, claiming they asked for more than one billion rupiah -- around USD 77,000 at the time -- to pass a prison sentence of less than 20 years.
It cited their then-Indonesian lawyer, Muhammad Rifan, who claimed a deal fell through after an intervention by Jakarta, which allegedly ordered the pair be given the death penalty.
He said he decided to go public given that the executions were imminent and that the Judicial Commission, the Indonesian body that safeguards the probity of judges, had yet to complete its investigation into the alleged requests for bribes.