A group of people thought to be migrants are brought in to Dover, Kent – charities say that children as young as 14 are being routinely assessed as being born in 1999. Photograph: Gareth Fuller/PA

Charities claim asylum seekers under 18 being classed as adults under Home Office age assessments

The Home Office has been accused of attempting to deport unaccompanied 16-year-olds to Rwanda in the first wave of asylum seekers to be sent to east Africa later this month.

Charities have identified what they describe as a “worrying pattern” of children being classed as adults by Home Office age assessments, raising fears they could be among those deported 4,500 miles to Rwanda.

One individual who said they were under 18 was placed in detention awaiting potential deportation to Rwanda and only released at the end of May, following intervention from lawyers.

Another two out of the 70 asylum seekers identified by one charity as having received warnings of imminent removal and currently held in immigration detention centres say they are 16, but their age is contested by the Home Office.

“We’ve got two age disputes but the Home Office has still issued notices of removal, ” said Clare Moseley, founder of Care4Calais, which is supporting the 70 and said legal challenges have been launched to help safeguard the “contested” children.

The anti-trafficking charity Love146 UK said several councils had flagged concerns about Home Office age assessments, stating that some children under 18 who had recently arrived by small boat across the Channel were receiving a “standard” age of 23, meaning they became potentially eligible for deportation to Rwanda.

Daniel Sohege, campaigns manager for Love146 UK, said: “We are seeing children as young as 14 being incorrectly age-assessed as 23. The number of children we have seen who have just had 1999 put down as their date of birth when they are clearly under 18 is highly concerning, and putting young people at risk.”

Lauren Starkey, a social worker for the charity, added: “It is not within the realm of possibility that anyone, especially someone trained in child protection, could look at the children we have seen and believe they are in their 20s.”

However, the Home Office says that “nobody will be removed if it is unsafe or inappropriate for them”, and denies that unaccompanied children would be relocated to Africa.

Last week, the home secretary Priti Patel announced that the first deportation flight to Rwanda would leave on 14 June, although lawyers believe it is unlikely to happen because of legal challenges against the controversial move.

Some believe the 14 June date was chosen simply because it comes less than a week before Boris Johnson is due to arrive in the Rwandan capital, Kigali, for the Commonwealth heads of government meeting, where he hopes to highlight the success of his Rwanda deportation plan.

Enver Solomon, chief executive of the Refugee Council, said: “The process that the government is adopting shows total disregard for the welfare and wellbeing of very vulnerable people, effectively treating them with contempt.”

He urged the government to immediately rethink its plans.

Among those served removal notices by the Home Office, increased mental health issues are being documented by charities. Moseley said a “high proportion” of the 70 they have identified have reported suicide attempts or self-harm. A five-day hunger strike among a cohort of those threatened with deportation at Brook House ended on Friday, although the Home Office has not altered its position.

In other developments, sexual maturity tests are said to have been carried out on child asylum seekers to determine their age, prompting outrage. Love146 UK’s Sohege said sources told the charity that police doctors had conducted sexual maturity ratings – used to assess adolescents’ physical development in puberty – on asylum seekers following arrest.

“The idea of sexual maturity tests being carried out is reprehensible. It is dehumanising, abusive and traumatic. Under no circumstances should they be conducted, yet we are hearing reports of just such tests happening in police stations,” he said.

Reports are emerging that unaccompanied asylum seekers being kept in hotels are going missing because of fears of being sent to Rwanda. Staff at one hotel on the south coast housing unaccompanied children had, according to Sohege, recently called police after hearing reports of three children climbing into a car and being driven away. Police were able to stop the car and return the youngsters, but the charity says it highlights the risk of exploitation and trafficking. “The obvious risks of them being exploited are incalculable and caused directly through government policy,” said Sohege.

A Home Office spokesperson said: “Adults passing themselves off as children is a serious safeguarding risk and in almost two-thirds of disputed cases from March 2021-22, the person was found to be over 18.

“Where a person has no credible evidence of their age, a thorough age assessment process will be followed. They will be treated as though they are a child until a decision on their age has been made.”