Swedish police have been drafted in to question the daughter-in-law of a woman known as the Black Widow as European authorities ramp up efforts to track down and detain her and her ISIS accomplices.
The 25-year-old woman, who has not been named, was captured last year by the Kurdish-led SDF after the battle for the last ISIS stronghold in Baghuz, north-eastern Syria.
A Swedish national, the mother-of-three was married to Ilyas Mejjati, son of Karim Mejjati, one of the main plotters behind the 2004 Madrid terror attacks in which 191 people were killed in co-ordinated attacks on rush-hour trains, and a 2003 attack in Casablanca, Morocco.
His mother, Fatiha Mejjati, gained her Black Widow nickname in the wake of Karim's death as she emerged as a member of Abu Bakr Al Baghdadi’s inner circle, and as an Al Qaeda and then ISIS operative.
She is known to have been close to the ISIS leadership around Baghdadi since 2014 and ran the group’s infamous Al Khansaa brigade, an all-female detachment that polices the group's strictures against wearing make-up or showing bare skin, and inflicts harsh punishments.
Her daughter-in-law is currently being held in a prison camp on the Turkish-Syrian border.
Authorities discovered she had been in contact with Mejjati by phone while in custody and have placed her in isolation.
Her mother-in-law is currently on the run after escaping from the Al Hol camp in north-eastern Syria a few months ago.
It is believed she is sheltering in Idlib with more than a dozen other women who were also part of the Al Hol breakout.
Swedish officers are to help interrogate the daughter-in-law in a bid to locate Mejjati, a source told Swedish paper Expressen.
However, they have not yet gained access to her as she is in quarantine.
“The SDF and the US military want information about the Swede's mother-in-law,” the source told the paper.
“If there is anyone who knows where the Black Widow is, it is her Swedish daughter-in-law. The Black Widow is very interesting for several intelligence agencies.”
Coalition forces have made efforts to locate Mejjati a priority. Officials believe she holds information about terror cells, contact networks and recruitment routes in Europe.
Her son had married the Swedish woman in Stockholm from where she travelled to Turkey in 2015.
The woman had been in contact with him prior to her departure and it is believed he helped her cross the border into Syria.
Mejjati is believed to have become radicalised following the Gulf War in 1990 and married in 1991.
The family moved to Afghanistan in 2001, where it is believed the couple established contacts in Al Qaeda training camps, and later travelled to Saudi Arabia after the US invasion.
Mejjati once told The National her time in Afghanistan under Taliban rule was "the most wonderful period" of her life.
Saudi authorities suspect Karim, a medical school drop-out, was responsible for the 2003 bombing of three foreign residential compounds in Riyadh.
In April 2005, Saudi police discovered Karim Mejjati’s hideout and he was killed alongside his son Adma during a firefight in the town of Ar-Rass.
Fatiha Mejjati was then arrested but was later released and sent to Morocco.