Almost 20% of unaccompanied kid migrants from Albania taken successful by Kent County Council this twelvemonth person disappeared, the BBC has found.
The section authorization took successful 197 Albanian children up to 31 October, 39 of whom person gone missing.
Ecpat UK, which campaigns to support children from exploitation, said the figures were precise concerning.
The assembly said it had worked intimately with the Home Office and constabulary to safeguard susceptible children.
The figures were obtained by the BBC via a Freedom of Information request.
The assembly said 197 Albanian children processed astatine the Home Office's Kent Intake Unit came into its attraction betwixt 1 January and 31 October.
It added that, arsenic of 7 November, 39 were recorded arsenic missing. However, it said immoderate of those children would person since turned 18.
Government figures collated by the BBC amusement 44,122 radical person crossed connected tiny boats truthful acold this year, compared with 28,461 who arrived successful 2021.
This contributed to overcrowding astatine the Manston processing centre successful Kent, which astatine 1 constituent was holding much than treble its capacity, astatine astir 4,000 people.
The rising fig of diphtheria cases among asylum seekers who person precocious arrived successful the UK has besides been a concern.
Meanwhile, a government program to nonstop immoderate asylum seekers to Rwanda is presently connected clasp arsenic it faces a ineligible situation successful the court.
Analysis: BBC newsman Simon Jones
For a section authorization which is taking connected the relation of a child's guardian, conscionable 1 young idiosyncratic going missing is 1 excessively many.
For Kent County Council, to not cognize the whereabouts of 39 of the Albanian children it was tasked with caring for indispensable beryllium highly worrying.
The assembly says candidly that it tin beryllium precise hard to forestall immoderate children from going missing.
It's trying to place proactively those who mightiness beryllium astatine hazard of exploitation, and, erstwhile missing children are found, it volition transportation retired a debrief to spot if lessons tin beryllium learned.
It has surely felt nether unit successful caller years implicit the fig of asylum-seeking children it has been required to instrumentality on, astatine times refusing to judge immoderate more, saying services were astatine breaking point.
Now, much unaccompanied children are being dispersed astir the country. But the situation of protecting those children from imaginable harm remains precise real.
More than 12,000 migrants from Albania person reached the UK by vessel truthful acold this twelvemonth - an summation of astir 4,000% compared with 2021.
The contented has been highlighted by Immigration Minister Robert Jenrick, who said that connected immoderate tiny boats 80% of those connected committee were from Albania.
Laura Durán, caput of policy, advocacy and probe for Ecpat UK said this was a "really high" fig of missing children.
She said: "We're truly acrophobic they are astatine hazard of exploitation oregon person efficaciously been trafficked.
"They could beryllium facing labour exploitation successful antithetic industries specified arsenic operation oregon car washes; they could beryllium criminally exploited successful cause organisation oregon successful cannabis farms, oregon they could beryllium sexually exploited."
In a statement, Kent County Council said it had seen a "significant increase" successful the fig of unaccompanied Albanian children referred to its services.
It said: "Whilst each unaccompanied asylum-seeking children are susceptible to exploitation... probe and acquisition evidences that immoderate nationalities are peculiarly susceptible and tin spell missing from section authorization attraction precise quickly.
"Kent County Council has utilized some established safeguarding protocols, including the National Referral Mechanism, and initiated multi-agency strategies to minimise the risks for these children arsenic overmuch arsenic possible.
"The assembly continues to instrumentality a proactive relation successful safeguarding each unaccompanied asylum-seeking children successful its care."