The Office of Fair Trading (OFT) has accused John Lewis, Debenhams and House of Fraser of colluding with a leading sports bra brand to fix prices.

The OFT alleged that manufacturer DB Apparel UK entered nine anti-competitive agreements with the department stores between 2008 and 2011. These alleged agreements had the aim of increasing the retail prices of its Shock Absorber brand of sports bras, which held approximately 15% market share, in the department stores.

The watchdog said that the agreements were a “serious infringement of competition law”.

OFT senior director of services, infrastructure and public markets Ann Pope said: “The OFT takes allegations of price-fixing seriously. Resale price maintenance limits competition between retailers and can lead to consumers paying higher prices.

“No assumption should be made at this stage that there has been an infringement of competition law. We will carefully consider the parties’ representations to the Statement of Objections before deciding whether competition law has in fact been infringed.”