Sports Direct boss Mike Ashley has admitted that he paid workers below the UK minimum wage.
Ashley also told the UK Business, Innovation and Skills select committee that he has discovered "issues" with working practices at the retailer as part of an internal review.
"I've discovered some issues and I've hopefully addressed some of those issues. Bottlenecks at security are the main issue," Mr Ashley told the UK committee.
MPs are investigating working practices at Sports Direct's Shirebrook warehouse, including poor working conditions, security staff searching employees, the use of controversial zero-hour contracts and paying less than the minimum wage.
Mr Ashley described the review as a "work in progress".
Mr Ashley was asked if employees were effectively paid less than the minimum wage, and answered: "On that specific point, for that specific bit of time, yes."
When asked whether it would be better if an independent organisation carried out a review of working conditions at Shirebrook, he said: "I can agree that in some ways I am not the right person because I am not an expert on every area of employment, obviously."
"It is not what I do for a living," he added.
He said he only spoke to the trade unions when they had the option to ask questions at the company's AGM, which is held once a year.
The businessman also pledged to implement a number of changes to working practices within 90 days, promising to write to MPs if the time frame needs to be extended.
On zero-hour contracts, Mr Ashley said his review had not covered that side of the business yet, but added that he agrees that some staff should be transferred to full-time contracts.
"Some of our top people have come from zero-contract employment," he commented.
However, he admitted that the 20% full-time and 80% part-time split of Sports Direct's workforce is the wrong balance.
When it was put to him that some female employees had endured sexual harassment, Mr Ashley described the managers as "sexual predators" who need to be "dealt with".
"It 100% should not be going on. They're repugnant, they're disgusting," he told MPs.
Mr Ashley agreed that Sports Direct had become too big for him alone to manage and vowed to review the firm's corporate governance structure.
After a four-month stand-off Mr Ashley finally agreed on Sunday to appear before the UK Business, Innovation and Skills select committee.
He had previously refused to attend, saying he would comply only if politicians first visited Sports Direct's warehouse and headquarters in Shirebrook.
They declined. Faced with a protracted legal battle, Mr Ashley had a change of heart, agreeing to attend without pre-conditions "in order to defend the good name of Sports Direct."
The retailer has been criticised by media and politicians for the treatment of warehouse workers at Shirebrook.
In December Mr Ashley pledged to oversee a review of all agency worker terms to ensure Sports Direct is meeting its legal obligations and providing a good environment for its workforce.
The last few months have seen a dramatic decline in fortunes for a firm that has a presence on most UK shopping streets, offering low priced sports goods through its 450 stores.
The company has issued two profit warnings this year, its shares have slumped 37% in 2016 and in March it lost its place in Britain's blue-chip FTSE 100 index of leading shares.
In terms of market capitalisation it has also been overtaken by rival JD Sports Fashion.
Mr Ashley, who is Deputy Chairman of Sports Direct and holds 55% of its equity, has said "media intrusion" has hurt the company's results.
Analysts say its problems are more to do with poor moves on acquisitions, increased competition and consumers growing tired of its cluttered stores.
As well as his retail business, Mr Ashley owns UK soccer club Newcastle United, relegated last month from the Premier League.
Sports Direct is also a major shareholder in the Heatons chain here, while last month the company bought the site of the former Boyers department store on North Earl Street in Dublin.
Investors reacted to Mr Ashley's performance by piling into Sports Direct's stock, boosting the share price by 5.78% this afternoon.
