Four people have been fined £10,000 for failing to declare they had travelled to the UK from a “red list” country, police said.
The four arrived at Birmingham airport on Monday and were not allowed to leave.
Chris Todd, temporary assistant chief constable at West Midlands Police, told a meeting held by the force’s strategic policing and crime board: “By midday yesterday [Monday], on the first day of implementation, we have received six passengers who had declared travelling from a red list country, who were taken to the quarantine hotel.
“We also had four passengers who were identified as having travelled from a red list country, that hadn’t declared it.
“So there are some people who have attempted to hide their routes but that’s not worked out.
“They were identified and received £10,000 fines as a result.”
It is not currently known which red list country they had been to. The Independent has contacted West Midlands Police for further information.
Those travelling to England from 33 high-risk countries must quarantine in a hotel for 10 days at a cost of £1,750.
The four people fined had flown to Birmingham via a country not on the list.
Only people who are UK or Irish nationals or UK residents are allowed to enter the UK from a “red list” country.
Scotland has extended the requirement to isolate in a hotel to cover arrivals from any country, unless they have travelled from or via the common travel area, which includes the UK and Ireland.
This loophole led to a man and his daughter who entered the programme on Monday being allowed to leave after just one day and complete their isolation at home.
Chun Wong and eight-year-old Kiernan arrived at Edinburgh airport from the US via a connecting flight in Dublin, and were taken to a nearby hotel to begin their quarantine.
However, Mr Wong was later contacted by officials to tell him he did not need to abide by the rules.
Additional reporting by PA