The owner of Boots reportedly charged the NHS over £1,500 for single pots of moisturiser which were being sold elsewhere for less than £2.
The product was sold by BCM Specials, a supplier then owned by Walgreens Boots Alliance, Boots's parent company, in 2016.
According to the Times (paywall), BCM sold the NHS one 500ml tub of a cream made up specifically for patients with skin problems for £1,579. It could be bought elsewhere for £1.73.
"If companies harm patients and taxpayers by unfairly and inappropriately hiking drug prices they should expect vigorous regulatory and legal enforcement action," NHS England said.
The case is one of many where the NHS appears to have been overcharged for so-called "specials" - drugs which are custom-made for patients who need non-standard medicines and which are often ordered at short notice.
Unlike standard drugs, the prices of many specials are not regulated, meaning suppliers are free to set their own. Approximately 300,000 specials are ordered each year to the tune of £50m and the report found an enormous disparity between the prices the NHS pays for specials to a number of manufacturers.
Among the most striking cases, the health service was charged £1,323 for 400ml of an ointment for severe skin problems, for which it paid the equivalent of £1.90 one month later, and £45.47 for preservative-free eye drops that can be sourced for less than £1.
Walgreens Boots Alliance categorically denied overcharging the NHS and insisted that it had complied with regulations and legal requirements.
"Specials are unique items ordered at short notice," a spokesperson said.
"They are made by highly trained technicians in dedicated laboratories in the UK that source ingredients, produce and quality-check often on the same day, and as a single item.
"This process incurs high overheads, reflected in the final cost, which is set in line with the sector to reflect the bespoke nature of the products."