Travelers have been released from quarantine hotels after the government removed the red list.
The PA news agency understands they have been told they can leave from 4 p.m., about 12 hours after the requirement to self-isolate in a hotel was dropped for new arrivals.
It was reported that some travelers had left their accommodation before this date.
Only those who received a negative result from a coronavirus test result were allowed to leave.
Health Secretary Sajid Javid said released travelers “will get a refund for the part of the space they booked and did not use”.
People with a positive result, or those who are not fully vaccinated and who are in contact with a person with a positive result, must remain in quarantine.
Concern over the Omicron variant of the coronavirus has led to 11 African countries such as South Africa, Nigeria and Zambia being redlisted.
People arriving in the UK from these places were required to spend 11 nights in a quarantine hotel at a cost of £2,285 for solo travellers.
But Mr Javid announced on Tuesday that the list would be scrapped because the strain’s prevalence in the UK meant it was ‘now less effective at slowing Omicron’s incursion from overseas’.
Jonathan Mogford, who is head of the quarantine service run at the UK Health Security Agency (UKHSA), told the Commons Transport Committee on Wednesday that there had been “unprecedented rates” of positive Covid cases among red list travellers.
He said the latest figures suggest ‘nearly 5% of people in hotels are testing positive’.
There were “about 5,000 guests in this series of redlists”, he said.
His comments indicate that around 250 of those people have tested positive.
UKHSA chief executive Dr Jenny Harries said the travel restrictions had “a time and a place” to protect public health.
She told MPs the Red List had been rolled out ‘as a delaying tactic’, giving the UK ‘time to prepare’ for the Omicron variant.
But now that the strain’s growth rate in the UK is “significant”, it is “really important” that country-specific restrictions are lifted, Dr Harries said.
Travelers entering the UK must take a test before departure and self-isolate until they receive a negative test result after arrival.
Members of the committee and former Labor minister Ben Bradshaw claimed Transport Secretary Grant Shapps told him the travel test scheme was “useless”.
He said: ‘The Health Minister told me in the House yesterday that he thought they were unnecessary and the Transport Secretary told me last night in the Division lobby that he thought they were also useless.
“Someone is obviously holding them in place, who’s holding them in place?”
Dr Harries replied: “It is not for us to make decisions. We give advice to ministers and I cannot speak for any of the ministers you just mentioned.
Downing Street insisted the measures were not “unnecessary”.
The testing requirements “remain important to help prevent further seeding of Omicron in the UK”, the Prime Minister’s official spokesman said.