A Supreme Court judgement has revealed a “loophole in the law” that could prevent asylum seekers being deported if they are found to have lied about their real identities to get citizenship.

Two Albanians who pretended to be Kosovan refugees to stay in Britain have won a legal test case to prevent their fraud resulting in them being thrown out of the country. The men’s victory is expected to cost the taxpayer up to £1 million in legal fees.

More than 80,000 refugees from Kosovo fled the war in the Balkans in the 1990’s to claim asylum here. However, thousands of Albanians used that crisis to pretend they were from Kosovo fleeing war to claim Britain citizenship.

Among them was Dinjan Hysaj, who aged 21 pretended to be a child refugee from Kosovo and was given British citizenship. Agron Bakijasi, also from Albania, used a false name, pretended to be from Kosovo and lied about his age to secure citizenship.

However, 40-year-old Hysaj’s lies came to light in 2011 when he was jailed for five years for glassing a man in a Hertfordshire pub. Bakijasi’s fraud emerged after his partner returned to Kosovo, revealing his true identity.

After the Home Office applied to deport them, the men’s lawyers argued that lying to obtain such citizenship was not enough to strip them of it.