The newborn son of Shamima Begum has died, according to the Kurdish forces holding her in northern Syria.

The British teenager, who fled to Syria to join Isis, has been stuck in a displacement camp for the past month after being detained while fleeing Isis territory.

Her lawyer, Tasnime Akunjee, said he had received “strong” indications her son had died.

“We have strong but as yet unconfirmed reports that Shamima Begum’s son has died,” he posted on Twitter. “He was a British citizen.”

The Syrian Democratic Forces, the US-backed group that controls the camps where Isis families are being held, later confirmed the boy's death. A medical source cited by the BBC said the infant, Jarrah, was rushed to hospital yesterday morning with breathing difficulties and a lung infection. The source said the baby has already been buried.

Ms Begum’s baby is among dozens of infants who have died in the last few months after fleeing the diminishing territory of the Isis caliphate.

The 19-year-old arrived heavily pregnant at the al-Hol camp in early February, after leaving the last-held areas under the terror group’s control. She gave birth to her son there shortly after, having already lost two children.

The British government has stripped her of her citizenship, leaving her unable to return to the UK. But her son was born before it was revoked, and so remained a citizen.

Syria at war: Fleeing the caliphate Show all 14 1 /14 Syria at war: Fleeing the caliphate Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Zikia Ibrahim, 28, with her two-year-old son and 8-month-old daughter, after fleeing the Isis caliphate Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Men who fled the last Isis-held area of Syria line up to be questioned by American and Kurdish intelligence officials Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate A young girl pulls her belongings after arriving Richard Hall/The Independent Syria at war: Fleeing the caliphate An SDF fighter hands out bread to women and children after they arrive Richard Hall/The Independent Syria at war: Fleeing the caliphate Sita Ghazzar, 70, after fleeing from the last Isis-held territory in Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate A family from Russia who recently fled the last Isis-held area of Syria Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria. Richard Hall Richard Hall/The Independent Syria at war: Fleeing the caliphate Richard Hall Richard Hall/The Independent

Earlier this month, her lawyer said she was moved to another site over “safety concerns”. It is believed that she is now staying at Roj camp, east of the city of Qamishli.

The camps have been overwhelmed as more and more flee the last remaining areas of Isis. More than 62,000 are now living in al-Hol camp, surpassing its capacity and leaving thousands sleeping out in the cold.

It has also been announced that 100 people have died over the past two months on their way to the camp or shortly after arriving, two thirds being babies and infants.

Aid groups have been sounding the alarm over conditions in the camp for weeks. The International Rescue Committee (IRC), which operates at al-Hol, said it was now at “breaking point”.

“We have seen a staggering number of children die on the journey to al-Hol camp due to a combination of malnutrition and hypothermia,” said Misty Buswell, the IRC’s Middle East advocacy director. “There is now an urgent need for thousands more family tents to get to al-Hol to help shelter the latest arrivals as well as increased funding to support the health crisis unfolding at the camp.”

Many of those arriving at the camp are in extremely poor health, the IRC added. There have been hundreds of cases of malnutrition and diarrhoea, including 364 infants under the age of five.

Ms Begum was 15 when she and two other schoolgirls left their homes in Bethnal Green to join the terror group in February 2015. The attention on her case has sparked a debate over how the UK should deal with British citizens who went to join Isis.

The home secretary, Sajid Javid, stripped her of her citizenship and promised to block any British citizen suspected of joining Isis from returning to the UK.

He said of her case: “My message is clear: if you have supported terrorist organisations abroad I will not hesitate to prevent your return.”

Ms Begum’s family have been lobbying the UK government to repatriate her infant son. Last month, her sister, Renu, wrote to Mr Javid to say the family planned to challenge his decision to strip Ms Begum of her citizenship and that her potential return was “a matter for our British courts to decide”.

She said her family had lost Shamima to a “murderous and misogynistic cult” that had exploited her and “fundamentally damaged her”, leading to the “sickening” comments she has made in recent interviews, including the suggestion that the Manchester Arena bombing was “justified”.

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“We were pleased to learn from your comments in the Commons that you recognise my nephew, Shamima’s son, as a British citizen,” she wrote.

“As a family, we ask now how we can assist you in bringing my nephew home to us. In all of this debacle, he is the one true innocent and should not lose the privilege of being raised in the safety of this country,” the letter added.

But Mr Javid said he had considered the child’s interest when deciding to revoke Ms Begum’s citizenship.

Asked whether there was any plan for Ms Begum’s son, Mr Javid told the Commons Home Affairs Committee last month it would be “incredibly difficult” for the government to facilitate the return of a child from Syria.