Although no one has yet claimed responsibility, the December 5 kidnapping is believed to have been carried out by the Abu Sayyef Islamic terror group, who have made abductions and ransoms a trademark.
Nine other foreigners were taken in the area last year, and in the past three years Abu Sayyef has snatched citizens of the United States, Korea, Malaysia, Japan, Switzerland and Ireland.
The group also kidnapped 21 people from the Malaysian resort island of Sipadan in 2000 - released on payment of a US$15 million ($19 million) ransom, and took 20 others from a Philippines resort the following year.
Hostages have been killed when ransoms have been refused: seven were beheaded in 2007.
Reissuing advice first given last month, the Foreign Affairs Department has warned of a "heightened threat environment" in the holiday period and said Australians in western and central Mindanao, including the Zamboanga Peninsula and Sulu Archipelago, should leave immediately.
The Australian Government has established a taskforce to work with Embassy officials in Manila and Philippine authorities in a bid to secure Rodwell's release.
In the video obtained by the Age, Rodwell, a former soldier living in Mindanao, urges officials to help.
"To my family, please do whatever to raise the US$2 million they are asking for my release as soon as possible," he says.
'To the Government, to the Filipino Government ... I'm appealing to you, please help me to co-ordinate with my family to raise whatever money is being asked. To the Australian embassy ... this is your constituent appealing for his life and safety. Please help facilitate to give the group the demand.
"Yes, I was a former army soldier of my country but it is different, particularly the terrain.
"The only solution to ensure my safety is to go with whatever they need. If I'm given my last wish, my last wish is to please help me out of here alive, please Madame Ambassador."
The kidnappers sent the photographs with a demand for an initial ransom of 1 million Philippine pesos - about $28,900.
Rodwell's Filipina wife, Miraflor Gutang, who is in protective custody, has said she has no hope of meeting the demand, and the Australian Government's policy is to refuse to pay ransoms.
The Government has declined comment, but its embassy in Manila said it was working closely with Philippine authorities, who were taking the lead in responding to the kidnapping.
Suspicion has centred on Abu Sayyef, which aims to forge an autonomous Islamic state in Mindanao, its surrounding islands and the Sulu Archipelago.
