LONDON (Reuters) - Interior minister Amber Rudd said on Wednesday she deeply regretted failing to realize there was a widespread problem that some Caribbean immigrants who have lived legally in Britain for decades were being labeled illegal immigrants.

FILE PHOTO: Britain's Home Secretary Amber Rudd arrives in Downing Street, London, April 24, 2018. REUTERS/Henry Nicholls

Rudd told a parliamentary committee she had known about the problem for months and said officials were still checking how many people had been detained over their supposed immigration status.

“I look back with hindsight and I’m surprised I did not see the shape of it sooner,” Rudd said. “I bitterly, deeply regret that I didn’t see it as more than individual cases that had gone wrong that needed addressing. I didn’t see it as a systemic issue until very recently.”

Thousands of people from the so-called “Windrush generation” were invited to Britain to plug labor shortfalls between 1948 and 1971, but some of them and their descendants have been caught out by tighter immigration rules.

The issue has created anger in Britain after it was revealed some of these migrants have been made homeless, lost their jobs, threatened with deportation and denied benefits, raising awkward questions about how the pursuit of lower immigration sits alongside the desire to be an outward-looking global economy.

The crisis has focused attention on the role of Prime Minister Theresa May, who as interior minister set out to create a “really hostile environment” for illegal immigrants, imposing tough new requirements in 2012 for people to prove their legal status.

Rudd told the committee there was no evidence that any of these migrants had been kicked out of Britain as a result of the scandal after officials examined 8,000 deportation records dating back almost two decades.

But she admitted her department still had no idea how many migrants have been wrongly detained by immigration authorities - like the grandmother Paulette Wilson, who spent a week in detention after being told she was in Britain illegally.

Earlier, the opposition Labour Party leader Jeremy Corbyn called on Rudd to resign for a “cruel and misdirected” immigration policy that he said was responsible for the hardships faced by the Windrush generation.

“The current (interior minister) inherited a failing policy and made it worse. Isn’t it time she took responsibility and resigned?” he said.