A security consultant believes a ransom was paid to free seven men, including a New Zealander, kidnapped in Nigeria, but says no-one will ever admit it.
New Zealander, three Australians, a South African and two Nigerians - employed by Perth-based mining company MacMahon Holdings - released by the kidnappers.
The group were in a convoy on the outskirts of the city of Calabar in southern Nigeria when they were attacked by about 30 gunmen. Their Nigerian driver was shot dead during the attack.
The New Zealander who was abducted lives in Australia, and has been named in the media as Jamal Khan.
Prime Minister John Key has said Mr Kahn suffered "non-life-threatening injuries" during the kidnapping. He had earlier ruled out paying any ransom.
MacMahon Holdings would not say if it paid a ransom, while the Nigerian police said they rescued the hostages during a dramatic raid in which the kidnappers escaped.
Australian risk consultant Shannon Sedgwick told Morning Report he was sceptical of the police story, and it was more likely MacMahon paid a ransom.
"Of course MacMahon would not admit to that because it would open their employees, in the future, to be targets."
Mr Sedgwick said the it was good that there had been such a rapid release of the hostages, which was unusual.