Sports Direct founder Mike Ashley’s personal investment vehicle suffered a slump in profits last year amid a “tough trading environment” for the retailer.

The billionaire’s Mash Holdings posted a 47% drop in pre-tax profit to £278m in the year to April 26, 2016, despite growing revenues 2.4% to £3bn.

According to documents filed at Companies House, 22% of Sports Direct employees left the business during the year, up from 18.7% the previous year.

Sports Direct has faced criticism from MPs over its use of zero-hour contracts and working conditions at its Shirebrook warehouse, which have been likened to a “Victorian workhouse”.

Mash Holdings blamed a “tough trading environment” for poor earnings at the sports retailer, which suffered an 8.4% fall in underlying pre-tax profit to £275.2m in the year to April 24, 2016.

The Companies House filing suggested that Ashley had lent the group around £116m interest-free and did not take a dividend.

Mash Holdings, which also owns Newcastle United, blamed a “hugely disappointing season” for the football club for further denting profitability.

Newcastle were relegated from the Premier League at the end of the 2015/16 season, sparking a fall in ticket sales.

Revenues from the club, which has now returned to the Premier League after gaining promotion last season, slipped to £131m as the average attendance at its 52,000-seater St James’ Park stadium dipped below 50,000.