Online retailer Boohoo is investigating why the same items of clothing were sold for higher prices across a number of its fashion labels.
The BBC discovered that Dorothy Perkins and Coast, which are both owned by Boohoo, sold exactly the same coat but it cost £34 more at Coast.
There are price disparities across a range of Boohoo brands, which also include Oasis and Warehouse.
Boohoo said the "miscommunication was not intentional".
"All Boohoo group brands work independently, and so this miscommunication was not intentional as teams are not privy to what's being bought and sold across the other group brands," a spokeswoman for Boohoo said.
"Our internal investigation continues and we will be re-pricing all the crossover stock to be aligned."
The price disparity was revealed after reporter Jennifer Meierhans bought a coat from Coast - as a friend happened to buy the exact same coat from Dorothy Perkins.
The Dorothy Perkins branding appeared to have been cut from the care label in the coat sold by Coast.
Boohoo said the coat was first sold by Coast and has now been re-priced at £17 on both brands' websites.
Catherine Erdly, founder of The Resilient Retail Club consultancy, and a former senior merchandiser at Coast, said: "If all Boohoo are going to do is buy the same stuff and slap different prices on it then it's destroying that brand's identity."
She said that while each brand will have its own "architecture" for setting prices, it is likely Coast and Dorothy Perkins had benefited from some kind of trading "opportunity", where a supplier had stock and both companies needed coats.
"But if they're going to do things like that, they didn't do it in a clever way," Ms Erdly said. "The customer will sense that it's just trying to get as much as possible out of them."
She added: "There's no way a Coast garment could have sold at £17 without losing money, a garment made for the Coast brand would cost more than that to make."
There are a number of instances where the same item of clothing is priced differently across Boohoo's brands.
Natalie Hitchins, head of home products and services at consumer watchdog Which?, said loyal customers of these brands will be "shocked and disappointed to see these stark price differences between seemingly identical items of clothing".
She said: "People choose brands and stay loyal by expecting quality to match the prices they pay.
"Brands that offer a first-class customer experience and can be trusted are the ones that come out on top in our retailer surveys. This practice from Boohoo could risk undermining trust with customers."
Boohoo operates a number of different brands after buying up businesses when their owners fell into administration.
Boohoo bought Coast's online business in 2019 along with sister brand Karen Millen. While in February, it acquired Dorothy Perkins, together with Wallis and Burton, from failed retail group Arcadia for £25.2m
Boohoo said: "Stock of the item in question was purchased and live on site by Coast prior to The Boohoo Group's acquisition of the Dorothy Perkins brand."
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