Almost 5,000 refugee ‘children’ who have come to Britain in the past decade have been found to be adults.

Home Office figures reveal there have been 11,121 disputes over the ages of child asylum seekers in that period, with 4,828 – almost 45 per cent – found to be over 18.

Their treatment as ‘children’ would have left councils and local taxpayers facing a care bill of tens of millions of pounds a year.

Despite the concerns, the Home Office is advising its staff to only challenge the age of a ‘child’ migrant if they look ‘at least 25-years-old’, it has emerged.

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Migrants from the Calais jungle camp cover their faces as they arrive at the Home Office immigration centre in Croydon

The guidance by the Home Office suggests that asylum seekers should only be challenged about their age if they are found to be ‘significantly over 18’.

'SAFEGUARDING' STOPS HOME OFFICE CHALLENGING AGE OF MIGRANTS According to The Daily Telegraph a report by the Chief Inspector of Borders in 2013 disclosed that staff only challenge child migrants about their age if they look like they are aged over 25. The report states: ‘We found from staff interviews and our observation of a trainer, that staff were encouraged to use this option in the guidance when perceiving an applicant to be at least 25 years old. ‘One stakeholder report advocated using this policy “with extreme caution”, and we therefore found the Home Office’s use of an eight-year age gap to be reassuring as an example of safeguarding.’ David Simmonds, chairman of the Local Government Association's asylum, refugee and migration task group, said the age guidance had been in use for some time. Advertisement

According to The Daily Telegraph officials are being advised that the policy should only be used with ‘extreme caution’.

Conservative MP Philip Davies told an emergency Commons debate yesterday that the row risked undermining public confidence in the asylum system, saying: ‘People only have to see the pictures of the so-called child refugees to see that many of them are not children.

‘A large number of my constituents have contacted me to say how angry they are that we are being taken for fools, taken for a ride, and our generosity is being abused.’

The MP’s warning came as:

Screens were erected around an immigration centre as another busload of migrants claiming to be children arrived from Calais;

One of this week’s ‘child’ migrants was found to be an adult whose fingerprints were already on a UK database;

A foster couple told how they were asked on to house men masquerading as children;

Court documents revealed how supposed child asylum seekers were noted to have ‘deep broken voices’, grey hair and moustaches;

A poll found overwhelming support for dental checks to determine arrivals’ age.

Hundreds more migrants are expected to arrive in the next few days under an agreement to reunite child refugees with family in Britain, as the makeshift Jungle camp in Calais is demolished.

A wall, dubbed the Croydon Curtain, was erected after speculation about the ages of those coming into the country

Supporters outside Lunar House in Croydon. Home Office figures revealed that half of those challenged about being children were over the age of 18

Tory backbencher Mr Davies said the Government had a duty to ensure the children it accepted were genuine youngsters and not adults intent on manipulating the asylum system.

He warned: ‘If somebody claims to be 14, do we just accept it and send them to a local school, with all the obvious safeguarding issues that will be involved if they were actually adults?’

The emergency debate in the Commons was scheduled following a week-long row over the apparent age of the migrants arriving from Calais. One, wearing a hoodie, appeared closer to 40.

Another was reportedly found to be on the UK’s biometric database, meaning he has tried to enter Britain before, has a criminal record or could have been logged as an adult on an asylum programme in another EU country. It is understood he is not significantly older than 18.

HOW JUDGES RULED AGE CLAIMS WERE FALSE A children’s home in Birmingham questioned the age of an Afghan asylum seeker after the 12-year-old was found to be shaving – and was noted to have a ‘deep broken voice’. Birmingham City Council ordered an age assessment which ruled he was over 18 and one assessor said he appeared to have been coached to parrot stock phrases in a deliberate bid to dupe officials. Publicly-funded lawyers took the case to an immigration tribunal, which ruled he was probably a month short of his 18th birthday when he arrived in Britain in 2008, but 22 at the time of the tribunal in 2013. His asylum claim was rejected. An Afghan asylum seeker who claimed to be 13 when he arrived in Britain in 2008 was challenged after social workers spotted grey hairs. The teen claimed he had fled his home in Helmand Province after being injured in an airstrike. Croydon social workers noted he was shaving and had ‘a few grey hairs ’ but assessed his age as 16. When he was put in a young offenders’ institution in 2012 for theft, criminal damage and assault, he said he was ‘over 19’, so at least 20, and did not want to be treated like a child. An immigration tribunal ruled there was ‘no reasonable likelihood’ he was 13 on arrival, but was probably then 16. And an Iranian asylum seeker who said he was 14 when he arrived in Britain later applied for benefits saying he was really two years older. The teenager, who said he was fleeing political unrest in 2008, told social workers in Liverpool he was born in 1994, but claimed income support saying he was born in 1992. He was assessed as being 18 or 19, but a second assessment estimated 16. Publicly funded lawyers took his case to the High Court in 2010, and argued he was entitled to claim benefit owing to his official age of 16, despite his previous 14 claim. The judge ruled he was probably 16 but noted he had ‘manipulated’ the system. Advertisement

Citizens UK hold a 'refugees welcome' event outside Lunar House in Croydon as migrants arrive from the Jungle Camp, which is to be demolished

Immigration Minister Robert Goodwill insisted the Government carried out age assessments, including using physical appearance and demeanour. But he ruled out dental checks as ‘inaccurate, inappropriate and unethical’.

A YouGov poll of 1,608 people found 55 per cent supported dental checks, with only 26 per cent against.

Britain is one of only four EU countries not to use medical checks to verify the age of child asylum seekers. The others are Ireland, Cyprus and Slovenia.

JUNGLE DEMOLISHED ON MONDAY French officials will start demolishing the Calais Jungle camp on Monday in an operation expected to last five days. They are planning to bus 3,000 migrants to reception centres across France on the first day, with 4,500 more removed over Tuesday and Wednesday. Officials said they will keep going until the camp is completely cleared. The French interior ministry says there are 6,486 migrants in the Jungle, although charities put the true number at more than 10,000. As news of the demolition spread last night, migrants began rioting over their planned eviction, with a large group that gathered near the motorway being sprayed with tear gas by French police. Many are determined to maintain their homes in the camp because it is a relatively easy place to try and board ferries and trains heading for Britain. A Calais police source said they were ‘prepared for the worst’ adding: ‘Many extra police are being bused in, and riot control measures including a water canon are being made available.’ Charities also handed out letters warning: ‘If you try to stay ...it is very possible that you will be arrested and detained.’ Last night the Home Office said: ‘Our focus is ... transferring eligible children and young people from Calais to the UK before the camp clearance begins.’ Advertisement

The remaining 24, plus Norway and Switzerland, use doctors, dentists or psychologists to catch adults who are abusing the asylum system by pretending to be children.

A report by the European Asylum Support Office says hand, wrist or collarbone X-rays, dental X-rays and – in some cases – genital inspections are used.

Mr Goodwill admitted that one migrant in ten approaching Home Office staff in Calais claiming they should be allowed into Britain as a child turned out to be an adult.

Adults cheating the system could be unwittingly housed with children in care and sent to local schools, he said, because refugees required to undergo age checks are treated as a child until their assessment. Councils pick up the bill for all costs for child asylum seekers, including putting them in foster care or children’s homes and providing them with support, health care and education.

Such support costs an average of £50,000 a year per child, according to the Local Government Association.

But Home Office statistics revealed that last year almost two-thirds of the ‘child’ refugees questioned about their age were found to be over 18.

Of the 574 asylum applicants whose age was disputed, 371 were deemed to be adults. If unchallenged, council care for those ‘children’ would have cost taxpayers more than £18million a year.

Since 2006 there have been 11,121 age disputes, of which 4,828 were found to be adults. Their care as children would have cost more than £241million a year.

Councils say the cost of supporting genuine child refugees has already left them facing a huge cash shortfall.

Craig Mackinlay, Tory MP for South Thanet, said: ‘I am fully in favour of children being offered asylum with their family in the UK. But what we are seeing loses credibility of this laudable aim with a huge swathe of the UK public. I share the concerns of colleagues that these “children” are nothing of the sort.’

First it was blankets, now they're hiding behind screens to stop the taxpayer knowing the truth

By Arthur Martin in London and Glen Keogh in Calais for the Daily Mail

A huge screen was put up outside a British immigration centre yesterday in an attempt to prevent anyone seeing the latest arrival of child migrants.

The move came a day after migrants who appeared older than typical teenagers used Home Office blankets to hide their faces as they walked into the centre.

A scaffolding company received a frantic call from the Home Office yesterday morning asking for a 15ft-high barrier to be erected before the refugees arrived.

Cloak of secrecy: Home Office guards patrol the screen yesterday at the Croydon centre

Five builders put up the screen in three and a half hours. Home Office security guards patrolled outside the centre in Croydon, south London, as the fifth group arrived from the Jungle camp in Calais.

Charity workers privately admitted that the construction of the screen was ‘farcical’ because many who arrived yesterday had posed for pictures before they left France.

A teenager on the bus opens a curtain to give a peace sign after arriving in south London

Ironically, the latest batch of more than 20 refugees appeared to be the youngest so far. Ali Otaky, a 13-year-old from Afghanistan, said he was excited about his new life, but admitted that some of the migrants who travelled to the UK earlier in the week looked ‘too old’.

As the arrivals walked into the immigration centre, more than 100 charity volunteers, local vicars and other well-wishers cheered from behind the plastic screen.

Waving balloons and banners, they chanted: ‘Calais kids are welcome here.’