Ashley was appearing before the business, innovation and skills select committee, which is looking into working practices at Sports Direct. The discussion centred on the retailer’s Shirebrook warehouse in Derbyshire which has been the subject of criticism from trade unions and the national press.

Ashley told MPs that at a ‘specific time’ Sports Direct effectively paid workers less than the minimum wage because they were held back at the end of their shift and searched by security before leaving the warehouse.

The practice meant that staff were spending additional time on company premises and led to many being paid an effective rate of about £6.50 an hour against the then statutory rate of £6.70.

‘I've discovered some issues and I've hopefully addressed some of those issues. Bottlenecks at security are the main issue,’ Ashley said.

The existence of talks between the company and its staff on how to compensate for the failure to pay the NNW were revealed in other evidence, from officials at the union Unite.

An HMRC spokesman said: ‘This isn’t about doing deals. While we don’t discuss individual cases we won’t accept anything less than what’s owed. Our role is to investigate all cases where we believe an employer is not paying its workers the NMW to ensure those workers receive what they are owed under the law.’

The penalties for infringement of the NMW rules were revised on 1 April 2016 and apply to any notice of underpayment relating to a pay reference period beginning on or after 1 April 2016. The penalty percentage has been increased from 100% to 200%. The maximum penalty is £20,000 per worker.

To date, the record figure retrieved by the Department for Business, Innovation and Skills is the £1.7m paid by Total Security Services to 2,519 employees that was announced earlier this year. That figure does not include fines.