The CMA will examine whether the four pharmacies and convenience stores overcharged customers for hand sanitiser as Covid-19 took hold and the Government urged people to wash their hands regularly.

The regulator had previously identified hand sanitiser as the product suffering the biggest price hike during the pandemic, with companies suspected of excessive and unfair pricing.

The CMA has launched investigations under Chapter II of the Competition Act 1998 into suspected breaches of competition law by the four retailers.

This investigation is at an early stage and the regulator pointed out that “no assumptions should be made that competition law has been infringed”.

Neena Bhati, head of campaigns at Which?, says: “Which? has repeatedly exposed unscrupulous sellers for selling essential items, including hand sanitiser, at hugely inflated prices since the beginning of this pandemic. No-one should be allowed to get away with this, so it is good to see the competition regulator taking action to investigate businesses suspected of exploiting consumers.

“However the government should be making it easier for the CMA by bringing in new emergency legislation that will allow it to take swifter action to stamp out price gouging and ensure the price of essential items stay reasonable during crises.”

Which? found in April that basic products such as hand sanitizer, antibacterial wipes and baby formula were being sold online at “hugely inflated prices”.