A new video has emerged of an Australian kidnapped by suspected Muslim extremists in the Philippines, with the foreign office on Monday saying it proved he was still alive in late March.

Warren Rodwell, from Sydney, was seized from his home in the southern Philippine town of Ipil on December 5 and in January a video showed him pleading with authorities to do all they could to secure his freedom.

Australia's department of foreign affairs said Philippine authorities had received a second recording of the former soldier, confirming he was alive on March 26.

"We can confirm the Philippine authorities have received another video of Mr Rodwell. The video provides proof-of-life as at 26 March," a spokesman said.

"This is welcome given our ongoing concerns about Mr Rodwell's welfare."

The department declined further comment, saying it would not be helpful to Rodwell's interests.

However, the Australian Broadcasting Corporation said the new video showed him holding up a newspaper dated March 26 while making a plea for a ransom payment to be made to save his life.

In the January video, reportedly sent to his Filipina wife Miraflor Gutang, Rodwell, 53, said his captors were demanding US$2 million.

At the time, Philippine authorities said it was possible Rodwell was being held by the Abu Sayyaf, an Islamic extremist group founded in the 1990s with seed money from Al-Qaeda.

Australia said it was working closely with the Philippines and was in close contact with Rodwell's family, who did not want to comment.