The Telegraph claimed that it is possible to order the counterfeit stamps in bulk from China, with costs as low as 4p for a First Class stamp depending on the volumes involved.
The fake stamps are then sold via the internet or through independent retailers who may or may not be aware that they are counterfeit.
The Telegraph’s investigation has been picked up by mainstream news outlets including the BBC.
The price of postage has increased enormously in recent years. On 2 April the price of a First Class and Second Class stamps rose by 10p to £1.35, and 85p respectively.
The new-style stamps with barcode were introduced in 2022.
Recipients of items sent using stamps the Royal Mail detection systems deem to be fraudulent are handed a £5 penalty to retrieve their mail.
Printweek asked Royal Mail how many fake stamps it was detecting on a weekly or monthly basis.
The postal operator declined to supply any figures that would illustrate the scale of the problem.
A Royal Mail spokesperson commented: “We are working hard to remove counterfeit stamps from circulation. We regularly monitor online marketplaces to detect suspicious activity, such as sales of heavily discounted stamps and work closely with retailers and law enforcement agencies to identify those who produce counterfeit stamps.
“We work closely with a number of police forces across the country and in recent cases we have recovered stamps with a retail value of over £250,000.”
It also warned against buying stamps that were being sold at discounted prices.
The postal operator said that the introduction of the new barcoded stamps with added security features had made it harder for fraudsters to replicate stamps, and claimed that “as a result the number of counterfeit stamps has reduced by around 90%”.
“We want our customers to buy stamps with confidence. We strongly recommend that customers only purchase stamps from Post Offices and other reputable High Street retailers, and not to buy stamps online – unless from the official Royal Mail Shop.”
Royal Mail’s website also has guidance on how to spot counterfeit stamps.