Consumer group Which? uncovered a wide range of products for sale for inflated, and “often ridiculous”, prices.

The probe revealed consistent overpricing of household items, including cleaning products, thermometers, baby formula and tampons – products that are all currently in particularly high demand and hard to find on the high street.

Among the listings was a £40 thermometer on sale for £300 and a £3 bottle of disinfectant retailing for £29.99.

The price of a bundle of three bottles of Dettol spray and three packets of antibacterial wipes soared to £210 on eBay.

At the start of this month, the Competition and Markets Authority (CMA) warned that traders should not exploit the coronavirus outbreak to rip people off, and threatened to take strong action if the problem persisted.

Which? is calling on eBay and Amazon to take more effective action against third-party sellers trying to take advantage of consumers

Both online marketplaces claim to have removed listings and suspended or terminated accounts during the coronavirus crisis, however the Which? investigation shows more needs to be done.

Sue Davies, head of consumer protection at Which?, said: “Our investigation shows unscrupulous sellers are still cashing in on people’s fears by selling essential items at extortionate prices on eBay and Amazon.

“These companies must make good on their pledges to stamp out coronavirus profiteering, and if they fall short the CMA must be ready to take strong enforcement action.”