The Australian government says it believes one of its nationals held hostage in Iraq is still alive.
Mr Wood appeared at gunpoint in a released videotape
The statement came as an influential Sunni figure said he had been in contact with the insurgents holding engineer Douglas Wood, 63.
Mr Wood appeared in a video issued on Sunday pleading at gunpoint for the withdrawal of coalition troops.
Australia, a major US ally, has vowed to try to secure his release but said it would not change its stance on Iraq.
"We're certainly very confident he is alive and we're still very determined to get him out," Foreign Minister Alexander Downer told Australian radio on Friday.
He confirmed an Australian task force had gone to Baghdad this week.
"Attempts are being made at different levels to try and secure his release and it's a case of the less said the better," said Prime Minister John Howard.
"We haven't given up hope... We should be positive, but we should also recognise how very hard it is."
'Severe medical problems'
The statement came as Sunni tribal leader Sheikh Hassan Zadaan told the Sydney Morning Herald that had been in contact with the kidnappers.
He said Mr Wood was alive, being fed and was in good health despite his heart condition.
He would not confirm if he had seen the hostage, but said he had managed to successfully dissuade the kidnappers from executing him.
"I told them this man is not a spy and even though he worked for (US construction giant) Bechtel in the past, he now ran his own business," Sheikh Zadaan was quoted as saying.
Mr Downer and Mr Wood's brothers have made appeals on the Arabic TV station al-Jazeera for his release, citing his poor health.
"We are extremely concerned for Douglas's welfare. He is not a well man, with several medical problems needing constant care," said his younger brother Malcolm.
"He has a serious heart condition. In his current stressed environment, without medication, his health could fail him altogether," he added, as another brother, Vernon, stood beside him.
Mr Downer also said Mr Wood had a problem with one of his eyes.
Pictured sitting on the floor flanked by two armed men, the hostage is heard, on a tape released to journalists on Sunday, to call for US, British and Australian forces to withdraw from Iraq.
A sign on the tape gives the name of a militant organisation, the Shura Council of the Mujahideen of Iraq, which has claimed previous attacks on US and Iraqi troops.
Mr Howard immediately rejected insurgents' demands.
Australia has about 950 troops stationed in and around Iraq. It is in the process of sending another 450 troops there.