And if they are at potential risk then it means they are more likely to overstay the visa and slip under the radar as an illegal immigrant. The Government has previously estimated there could be as many as 570,000 illegal immigrants here but with so many visas being incorrectly issued over the years, that figure could now run in to the millions.
Costelloe-Baker said: "I don't think there has been adequate scrutiny of decisions to issue. I think there is pressure to issue visas because it helps people hit their productivity targets." Committee member and Tory MP David Davies asked if it was reasonable to assume that 15 per cent of approval notices were incorrectly approved.
"I think that's a reasonable supposition," Costelloe-Baker said.
Nearly two million visas are approved each year, giving foreign nationals the right to come to the UK for six months.
Embassies and consulates examine 2.4 million applications each year from tourists, businessmen and people visiting relatives to check if they intend to leave after their visa expires, that they have enough money to live in the country and are not looking for a job, she said. Around 80 per cent are approved.
Reasons for refusal can involve doubts over whether will return home when their visa expires, questions about their true reason for coming and even concerns over their identity.