The wife of the Paris supermarket gunman may be in Syria, police sources have said.
Hayat Boumeddiene, 26, is partner of Amedy Coulibaly, who killed a policewoman and then four hostages at a kosher bakery.
A police source said she flew to Turkey via Madrid on January 2, despite alleged sightings of her in Paris on Thursday.
Authorities in Istanbul then reported seeing a woman matching her description cross the Turkey- Syria border on Thursday, the day her husband killed policewoman Clarissa Jean-Phillipe.
Sources say she had a return ticket from Istanbul to Madrid for yesterday but failed to show for the flight.
Police were today interrogating the wives of the Kouachi brothers responsible for the Charlie Hebdo massacre in a bid to track down Boumeddiene.
Hundreds of phone calls between Boumeddiene and Izzana Hamyd, wife of Cherif Kouachi, have shown up on mobile records. Five hundred in all were made last year. The wife or girlfriend of the older Kouachi brother, Said, is also being held.
Image 1 of 13: Police officers prepare to storm a kosher grocery. Photo / AP
French Algerian Boumeddiene is now not thought to have been with Coulibaly at any time in the Kosher Supermarket and to have fled immediately after the killing.
Wearing a skimpy bikini with her arms wrapped around her lover's waist, this is Boumeddiene before she turned into a jihadi killer's accomplice and became France's most wanted woman.
Photographs of the 'wife' of the Kosher supermarket hostage killer reveal how she was radicalised by the man she would go on to marry.
Her husband Amedy Coulibaly is dead, one of the three terrorists who brought France to a halt in 48 hours of bloodshed.
Now, 26-year-old Boumeddiene is on the run and is believed to be 'armed and dangerous'.
Coulibaly died in a hail of bullets along with four hostages in the storming of the Jewish supermarket.
The couple 'married' in a religious ceremony after Boumedienne, who was never seen without her veil, waited four years for him to come out of jail following his conviction for armed robbery.
Like her husband she was born into a large family, seven children, in 1988 but when she was just six years old, her mother died.
The eldest children left home, according to reports in Le Parisien, and social workers took over. It is suggested that Boumeddiene may have been put into care.
Estranged from her father, she met him briefly once more and introduced him to Coulibaly.
But all may not have been as settled as the young woman, radicalised by her husband, thought.
It is understood he had made it clear he wanted to take a second wife, according to other reports.
Today, questioned by police at his home in Nanterre, a Paris suburb, Boumeddiene's father is said to be shocked and unable to believe that his daughter was involved with the terrorist cell.
But it is becoming clear that the one-time cashier was radicalised after meeting the man she would marry.
She is from an Algerian background and altered her surname to 'make it sound more French', according to an investigating source.
She told police who interviewed her as part of their inquiries into Coulibaly's murky dealings with Islamic extremists that she had walked away from a low-paid job as a cashier in the Juvisy suburb of Paris in 2009 and taken the veil. She 'devoted herself' to Coulibaly.
Interrogated by police in 2010, Boumeddiene said she was inspired by her husband and the radicals she lived with to 'read a lot of books on religion and because of this, I came to ask questions on religion'.
'When I saw the massacre of the innocents in Palestine, in Iraq, in Chetchna, in Afghanistan or anywhere the Americans sent their bombers, all that... well, who are the terrorists?'
She added that when Americans killed innocents, it was the right of men to defend their women and children.
Always cool and composed, Boumeddiene never wavered under police cross examination.
When told that they knew she and Coulibaly had visited Beghal at the same time as Cherif Kouachi and two other convicted terrorists, jihadi recruiter Ahmed Laidouni, and Farid Melouk of GIA, she replied: 'We went there for crossbow practice.'
The couple lived in nearby Bagneux, where they were known as a devoutly religious couple, despite Coulibaly's regular run-ins with the law.
To neighbours the pair were quiet, respectful and normal and had even gone on a holiday to Malaysia together.
But a month ago they simply disappeared from their suburban house until flashed across the world's screens today.
Coulibaly murdered at least four hostages at the Kosher supermarket in Paris, according to Reuters news agency.
He is believed to be part of an Al Qaeda terror cell linked to a British-based jihadi extremist, Djamel Beghal.
The 50-year-old preacher, who recruited terrorists while worshipping at London's Finsbury Park mosque, met Cherif Kouachi while in prison in Paris.
Coulibaly has a long history of both petty and serious crimes. The only boy born in a family of ten in Juvisy, Essonne, he first came to police attention as a 17-year-old delinquent.
Convictions for theft and drug offences followed. In September 2002 in Orleans, Loiret, he was arrested for the armed robbery of a bank.
It's believed he became involved with the younger of the Kouachi brothers, Cherif, when he was part of a jihadist recruitment ring in Paris that sent fighters to join the conflict in Iraq. Kouachi was subsequently sentenced to three years in prison.
The two sieges by suspected Islamic terrorists played out at the same time, as fears grew that they would be looking to cause another bloodbath.
Cherif was convicted in 2008 to three years in prison, with 18 months suspended, for his association with the underground organisation.
He had wanted to fly to Iraq via Syria, and was found with a manual for a Kalashnikov - the automatic weapon used in Wednesday's attack.
Said was freed after questioning by police, but - like his brother - was known to have been radicalised after the Iraq War of 2003, when Anglo-American forces deposed Saddam Hussein.
Both brothers were said to be infuriated by the killing of Muslims by western soldiers and war planes. Vincent Olliviers, Cherif's lawyer at the time, described him as initially being an 'apprentice loser - a delivery boy in a cap who smoked hashish and delivered pizzas to buy his drugs.
But Mr Ollivier said the 'clueless kid who did not know what to do with his life met people who gave him the feeling of being important'.
Belkacem was a leading members of the GIA, or Armed Islamic Army - an Algerian terror outfit responsible for numerous atrocities.
The Kouachi brothers, who are orphans, were radicalised by an Iman operating in northern Paris.
They were raised in foster care in Rennes, in western France, with Cherif training as a fitness instructor before moving to Paris.
They lived in the 19th arrondissement and were radicalised by Farid Benyettou, a janitor-turned-preacher who gave sermons calling for jihad in Iraq and suicide bombings.
The Kouachis share similar backgrounds to Mohammed Merah, the 23-year-old French Algerian responsible for murdering seven people, including four Jews and three Muslim soldiers, in the Toulouse area in 2012.
Merah, who was himself shot dead by police, had also been left to operate as a terrorist in France, despite the authorities knowing he had trained with Al Qaeda in Afghanistan.