JD Sports saw record profits jump more than 80% as the sports chain rejected accusations of "prison" conditions at a key warehouse.

Channel 4 reported last year that workers at the Kingsway site in Rochdale, Greater Manchester, were subject to a "three strikes" policy under which they could be fired for chewing gum or sitting down. It employs over 1,000 staff and agency workers.

But the retailer said the allegations did not represent "a balanced characterisation of working practices at the site," following an independent report carried out by accountants Deloitte.

The firm posted pre-tax profits that soared by 81% to £238.4m in the year to 28 January compared to a year ago, as it rode the fashion for wearing running shoes and tracksuits as everyday clothing.

The group – which runs over 4,000 stores across Europe, Asia and Australia – said "athletic inspired footwear and apparel has been on trend throughout Europe for a number of seasons", adding this had been "a positive influence".

The company has 900 outlets are in the UK. The group opened 54 stores across Europe last year and a further two in Malaysia. The first JD store in Australia is due to open shortly.

Executive chairman Peter Cowgill said: "Whilst we must recognise that there are external influences which may impact the latter part of the year, notably inflationary pressures arising from Brexit, the board remains confident in the robustness of the JD proposition and believes that the group is well positioned for further profitable growth."

Shore Capital Markets analyst George Mensah said: "We remain bullish on the company as we believe it is one of the strongest plays in the retail sector."

Shares lifted more than 7% in early trading.