Inspectors are demanding the immediate release of loyalty card statements in order to trace customers? payments to retailers back to private bank accounts and credit cards.
According to Digita.com, two supermarket chains have already provided customer information to them.
It is feared that the next move will be DIY chains such as Homebase and Wickes, where small jobbing builders often buy materials.
By comparing spending records with bank statements, the Revenue might discover undisclosed bank accounts or large cash payments.
Latest Tesla news: Tesla stock price tanks amid reports of 'widening probe' by SEC and claims the base Model 3 loses money
SEC 'probe' takes its toll on Tesla as new research suggests that Tesla loses $6,000 on every $35,000 Model 3
10nm Cannon Lake Core i3-8121U CPUs make a rare outing with Intel's NUC mini PC
'Notorious' Australian child hacker thought he had executed 'flawless' hack
The former employee says that Tesla fired him for bringing the accusations to management internally