Sports Direct founder Mike Ashley has admitted to problems with some practices at the firm's Derbyshire warehouse, ahead of him facing MPs.
In a letter to staff, made public on Monday, Mr Ashley said the centre needed improvements to its security procedures, which had now been made.
The retailer has been criticised for the centre's working conditions.
Mr Ashley said chief executive Dave Forsey would also not receive his £4m bonus due to the "difficult year".
The Newcastle United owner is due to appear before the Business, Innovation and Skills select committee later.
Mr Ashley had previously refused to face MPs, but on Sunday he decided that he would give evidence to defend the firm's "good name".
The billionaire had urged MPs to visit the warehouse in Shirebrook before agreeing to give evidence.
