A videotape of a French journalist held hostage in Iraq is the second to be released, says the French government.
Ms Aubenas says she is suffering physically and psychologically
Prime minister Jean-Pierre Raffarin said they received a first tape of Florence Aubenas last week, which had been shown to her family.
Ms Aubenas, of Liberation newspaper, is thought to have been snatched along with her interpreter, Hussein Hanoun al-Saadi, in Baghdad on 5 January.
Looking thin and exhausted on the latest tape, she appealed for help.
"We are very concerned by the situation," Mr Raffarin told reporters.
"We already had a video document last week, which we showed to the family. At the moment, laboratories are analysing this second document to find out whether it (was made) before or afterwards."
He said the government was "very mobilised" to secure the captives' release.
In the new video, broadcast by Sky Italia news channel, Ms Aubenas looked distraught, clutching her knees to her chest. She had bedraggled hair, and wore a grey sweatshirt and black trousers.
"My name is Florence Aubenas. I'm French. I'm a journalist with Liberation," she said in English.
"My health is very bad. I'm very bad psychologically also."
There had been little news on Ms Aubenas since her disappearance.
Liberation's foreign editor, Francois Sergent, said the emergence of the video was "both what we feared and what we hoped for".
"It is a sign that they are alive, of course, but we also feared this because the hostages are being held in conditions that make the pictures terrible to see."
Ms Aubenas is at least the third French journalist to be kidnapped in Iraq. Two others, Georges Malbrunot and Christian Chesnot, were freed late last year.
They had been held for nearly four months.
Plea to MP
On the tape Ms Aubenas, 43, appealed for help.
"This is urgent now. Help me! I ask especially Mr Didier Julia, the French deputy. Please Mr Julia. Help me! It's urgent. Mr Julia help me!" she pleaded.
Mr Julia, an MP for President Jacques Chirac's ruling UMP party, led a failed mission last year trying to secure the release of Mr Malbrunot and Mr Chesnot.
He was condemned in France for taking unilateral action and jeopardising official attempts to free the men.
Two of his assistants are under investigation for their role in the venture, and Mr Julia said he would seek the French government's permission before responding to Ms Aubenas' request.
Two weeks ago an Italian reporter, Giuliana Sgrena, was shown on video begging for help after her own kidnap in Iraq.
Ms Sgrena, who works for the Italian Il Manifesto newspaper, urged foreign troops to leave Iraq.
There has been no news of her since.