The founder of homewares retailer Dunelm, Bill Adderley, has been revealed as the biggest private shareholder in Marks & Spencer.

His stake in the company was made public after it topped 3%, worth £244m at Thursday night’s closing share price, the Telegraph reported.

Shares in M&S spiked on Thursday after Adderley’s investment was revealed. The retailer closed up 10.3, or 2pc, at 503½p.

It is thought the Dunelm founder started buying shares in the past 18 months, but that his interest only became public after his investment in the company crossed the 3% benchmark.

Adderley’s investment in M&S is a vote of confidence in the business, which has had a difficult past couple of years in non-food categories. Earlier this week Retail Week revealed it had slowed its decline in the clothing sector. Sales fell 0.2% in the 24 weeks to the end of September, compared with a 0.5% fall in the previous period.

Adderley is no longer involved in the day-to-day running of Dunelm, having passed control over to his son Will in 1996.