It has been revealed that nearly a third of people arriving into Northern Ireland and England this spring may have broken quarantine rules.
More than 300,000 cases were referred to the Home Office for "extra checks on their whereabouts" after they were suspected of going against regulations at a time when the Delta variant was beginning to rise.
The figures, released through a Freedom of Information request by the BBC, were grouped together and did not detail the exact location.
New rules were introduced earlier this year for people arriving from abroad in an effort to slow the spread of coronavirus while reducing the arrival of new variants in the region.
People arriving from high-risk countries, known as 'red list' countries, had to quarantine in a hotel while those from medium-risk 'amber- countries were required to self-isolate for 10 days and show evidence of negative Covid tests.
From March 17 to May 31 more than a million people arrived in England and Northern Ireland from amber list countries.
Call handlers employed by the Department of Health were tasked with contacting arrivals to check they were following self-isolation and testing rules.
Cases where the contact ended the call, refused to co-operate, indicated they would break the quarantine or testing rules, or could not be contacted after three attempts were referred to investigators at the Border Force Criminal Justice Unit and the police.
Officers would then attempt to visit the contact at home to check they were following the rules.
The Home Office stated it aimed to visit over 99% of people who were due to be self-isolating.
The latest travel rules and regulations can be found on the NI Direct website.
Get the latest news headlines straight to your inbox by signing up for free email alerts
