Unaccompanied asylum seeking children are being held in detention unlawfully, an immigration welfare charity has alleged.

Detention Action have sent a letter to Kent County Council (KCC) outlining their accusation and demanding a justification.

After KCC announced they could no longer safely take care of unaccompanied children arriving on Kent's coast, the Home Office began holding new arrivals in the Kent Intake Unit, a short-term holding facility under the department's detention powers.

The letter said: "It appears to us... Kent is unlawfully abdicating its statutory obligation to care for children in need in their area and further putting the children at risk of harm to their welfare by causing them to be detained and deprived of their liberty in an administrative way without oversight."

Detention Action points to KCC's duty to find accommodation for lone children in need under the Children Act 1989 and Children Act 2004 if no one else will provide this.

The charity also refers to the procedure in the The Immigration Act 2016 which allows children in need of care to be transferred to other local authorities.

The letter goes on: "We fail to see why this process - directed precisely at dealing with pressures that a local authority in Kent’s position may face - cannot be used and why Kent considers it acceptable and lawful to abdicate non-derogable child safeguarding and protection obligations."

The letter ends by asking for clarification on why lone migrant children are being detained and how KCC and the government have been managing the county's care capacity issue.

A Home Office spokesman said: “We are working hard with the French to make this route unviable and to reduce the number of unaccompanied asylum seeking children reaching the UK in this way.

“This is an unprecedented situation. We continue to provide Kent County Council with support, including significant increases in funding, but the burden being placed on them is unacceptable and cannot continue.”

The Home Office told the Huffington Post children were being held in detention but are prioritised to remain there for only a short time while checks are made, after which they will go to social services.

However, the Home Office have not yet made public how many children are being held in detention and the duration of their time there.

A KCC spokesperson said: “KCC received a legal enquiry from Detention Action yesterday and it is now in the hands of our lawyers who will respond in due course.”

Read more: All the latest news from Kent