Canberra, June 1 : Australian mining giant, BHP on Thursday apologised for underpaying its former and current workers across the country for 13 years. In a statement, Geraldine Slattery, BHP's Australia president, said: "We are sorry to all current and former employees impacted by these errors. This is not good enough and falls short of the standards we expect at BHP. We are working to rectify and remediate these issues, with interest, as quickly as possible," the BBC reported. A review conducted by the Melbourne-based company revealed that around 28,500 employees received less holiday than they were entitled to, while 400 workers did not get additional allowances "due to an error with the employment entity". The review further showed that some affected employees had their leave incorrectly deducted on Australian public holidays, and as a result they were owed a total of six days of leave on average. The firm said that it has reported the incident to the authorities and the errors will cost the company up to $280 million before taxes, reports the BBC. BHP also said it has commissioned a review of its payroll systems, adding that it would provide an update on its investigations during its full-year earnings call in August. The world's biggest miner, BHP has around 80,000 employees and contract workers at sites including the Escondida mine in Chile, which is the largest copper mine in the world. /IANS