The UK firm owes workers £2.4m
Argos will have to pay £2.4m (€2.8m) to more than 37,000 current and former employees after the British firm was found to have paid workers less than the minimum wage.
This was the result of a HMRC investigation - it relates to the company requiring staff to attend briefings and to carry out security checks outside of their working hours without compensation.
The practice was discovered as part of a review of its operations following its sale to Sainsbury's.
John Rogers, the CEO of Argos who was appointed after the takeover said in a letter to staff, "Sainsbury's prides itself on being a trusted brand where people love to work and I was, therefore, very disappointed to hear this and launched an immediate investigation."
He added that the company has stopped this practice.
The average worker affected by this finding will receive £64 - this will be paid on February 28th. 12,000 of the employees still work for the company.
Sainsbury's paid £1.4bn for the high street retailer last year.
British authorities recently 'named and shamed' 350 companies who were found to have underpaid workers.
Debenhams has also been accused of underpaying 12,000 workers.
"Every worker in the UK is entitled to at least the national minimum or living wage. That is why we named and shamed more than 350 employers who failed to pay the legal minimum this week, sending the clear message to employers that minimum wage abuses will not go unpunished," the UK's Department for Business, Innovation and Skills commented.