The government has pledged to stop car clocking following an exposé that revealed that up to 100 firms are offering services to digitally alter cars' odometers.
It is currently illegal to sell a clocked car without declaring its genuine mileage, but the actual act of altering the car’s odometer is not an offence.
Following The Sun's investigation, the loophole is set to be removed, with business minister Anna Soubry saying: "We [the government] will stop it."
The European Parliament earlier this year announced plans to ban companies that offer mileage-altering services from May 2018, but it is not clear whether any changes to the UK's law will come into affect before that date.
"The government will look into this matter,” a spokesman said.
“Clocking with the intent to sell is a criminal offence and any suspected breaches should be passed on to Trading Standards to investigate."
Altering the digital reading can put other things controlled by the ECU out of sync, such as safety warnings.
There could be as many as 1.7 million used cars on UK roads with fraudulent mileage readings, according to vehicle history checking company HPI.
The firm backs the government’s pledge to clamp down on car clocking and has released some estimates of how mileage reduction impacts used car prices.
HPI says a three-door Ford Fiesta 1.25 Zetec from 2012 is worth £4795 with an odometer reading of 90,000, but its value rises by £1655 to £6450 with 30,000 miles on the clock.