It's the news many are unlikely to believe, but new data collected by a Galaxy poll has revealed that 90% of high income bracket employees work harder and regularly perform unpaid overtime.

According to the Galaxy poll of over 800 working Australians, 88% of workers said they had worked extra hours in the last six months, but the figure increased markedly with salaries. For workers earning less than $50,000 per annum, 80% said they had worked overtime, but only 37% said they had been unpaid for their extra hours.

A whopping 63% of respondents who fell in the $50-70,000 pay bracket said they had worked extra hours without monetary compensation for time. With the average national wage sitting at $67,891, nearly all respondents who reported earnings in excess of $70,000 said they had gone "above and beyond" what was officially required of their job description, with 70% reporting they did not receive an overtime allowance.

But why are Australians so willing to work for free? Organisational development consultant Dr Darryl Cross told the Courier Mail that workers on higher salaries were often prepared to put in more hours because of their pay level.

"At the executive level, or the managerial level, there's a perception they are expected to work harder," Cross said. In survey results released late last year by the Australia Institute, it came to light that Australians work more unpaid overtime than almost any other country in the world.

The survey found that despite the flexible labour market, only one in five employees are working the hours they want to work. According to the data, this imbalance was found to be seriously affecting the health and well-being of Australia's workforce.

50% of respondents said work prevented them from spending enough time with the family in the week leading up to the survey, and the same figuresaid work stopped them doing physical exercise and also negatively affected their eating patterns.

Speaking to ABC's Lateline, Josh Fear from the Australia Institute said that looking only at employees (not business owners), "Australians work the longest hours in the Western world and we're only beaten by Japan and Korea."

He added, "And of course the Japanese have a word for death by overwork..I don't think we want to get to that point."

According to the study, Australian workers donate two billion hours of work worth $72bn (accounting for 6% of Australia's GDP) to their employers each year.