Holidaymakers are thought to be spending more than £11 million on PCR tests for travel, at a cost of £75 each on average.
The tests have been designed to enable the government to detect the import of variants that could "threaten" the vaccine programme - but more than 40% of the results from the 350,000 PCR tests a week on amber list travellers are being recorded as "unregistered".
The Telegraph, citing "experts", reports that without this data, it would be very difficult for the government to trace individual travellers involved in any outbreak of a new variant that has entered the UK.
