"The employer claimed these were just people who "helped out''.
"It kept no employment agreements or records for these workers.''
Labour Inspectorate regional manager Jeanie Borsboom said the Labour Inspectorate occasionally encountered people working informally at businesses, but said any work by employees for gain or reward must be properly documented under New Zealand legislation.
"Even if the work is casual or short term, employers must keep written employment agreements, records of hours, wages and leave, and provide at least the minimum wage and minimum holiday pay entitlements.''
The Labour Inspectorate lodged the case with the ERA after the business failed to respond to an improvement notice.
The eight people working for Grocery King included both New Zealand citizens and migrants.
All arrears of about $1800 have been repaid.
"The penalties of nearly $54,000 on top of these arrears send a clear message to employers that they cannot bypass their obligations or attempt to conceal information from the Labour Inspectorate.''
Anyone concerned about the employment situation of themselves or someone they know is advised to call its contact centre on 0800 20 90 20, where their concerns will be handled in a safe environment.