The Austrian press has identified the two hostages as Wolfgang Ebner, 51, and Andrea Kloiber, 44.
Their exact whereabouts are unknown, with the authorities in Algeria and Tunisia say they are in the other's territory.
Vienna said this week that it was doing all it could to find the two and that an extensive search was under way in an area the size of Austria.
Relatives reported the pair missing when they did not return from a holiday to Tunisia on March 1.
The two were last heard from on February 18 and failed to make a planned phone call to Ebner's son on February 25.
Austrian media identified Ebner as a tax consultant from the town of Hallein, and said Kloiber is his girlfriend.
The authorities began a search for the two tourists after Al Jazeera's Arabic channel aired an audio tape, said to be from al-Qaeda's North African branch, which linked the abduction of the consultant and nurse to the violence in Gaza.
It said the man and woman were taken on February 22 and that they were in good health.
The tape also warned Western tourists to stay away from the Maghreb region of North Africa of which Tunisia is a part.
"We tell Western tourists flocking to Tunisia for leisure at a time when our brethren are being slaughtered in Gaza by the Jews with the complicity of Western states ... the apostate Tunisian state is not able, and will not be able, to protect you," the voice on the tape warned.
The Tunisian government said it had carried out "intensive search operations" but there was no proof of the two tourists being in the country.
It said the Austrians were last heard of crossing the Sahara desert in a direction that would have taken them out of Tunisia.
Meanwhile, the US state department issued a warning to travellers to Tunisia in the wake of the kidnappings.
"Al-Qaeda Islamic Maghreb is designated as a terrorist organisation by the United States, and its presence in North Africa presents potential dangers to travellers," the statement said.