A cleaner was fired for having a cup of coffee on the job as his employer considered it theft.

The international student, who worked part-time for Glad Group Pty Ltd, arrived 45 minutes early to work in a Sydney office, where he said staff had told him he was welcome to a cup of coffee when he was cleaning, in January.

A manager at the office, who saw the cleaner and his colleague drinking the coffee, complained to Glad Group Pty Ltd.

A cleaner was fired from his job after having a cup of coffee while working because his employer considered it theft (stock image)

She had told them, 'You are not allowed to make coffee', to which the cleaner replied, 'We are sorry, we did not intentionally want to upset you. We did not know we were not allowed to'.

Despite the apology the manager lodged a complaint and said she did not begrudge anyone a cup of coffee but did like they were drinking it 'without my knowledge'.

Glad Group Pty Ltd dismissed the cleaners for serious misconduct two days later as the company classified the cleaner taking a cup of coffee as theft.

But Fair Work Commission vice-president Adam Hatcher did not agree with the cleaner's dismissal and found it was 'unjust and unreasonable'.

'I consider that the conduct upon which his dismissal was based was insignificant to the extent that it could not constitute a sound, defensible or well-founded reason for his dismissal,' Mr Hatchet said.

'In my view, any reasonable person would regard his conduct as involving no more than a trivial misdemeanour. Glad characterised his conduct as being an act of theft.

'I prefer to take a more commonsense approach to Glad's characterisation of [the cleaner's] conduct.

'In my view describing his conduct as "theft" verges on an abuse of the English language as used and understood by the ordinary person, having regard to the following circumstances.'

Glad dismissed the cleaners for serious misconduct, despite their explanations and apologies for any misunderstanding (stock image)

Mr Hatcher said Glad Group Pty Ltd's definition was 'absurd' and based on this rule of thumb 'the consumption of a glass of water drawn from a client’s tap on a hot day would also constitute theft'.

'The use of a client's toilets to answer an urgent call of nature without express prior permission would be a trespass. It is an approach which, for the reasons stated, I reject,' he said.

Mr Hatcher also went onto to say the cleaner was 'an honest and honourable man' and this dismissal would put a blemish on an otherwise good work record.

'As an international student with limitations on the hours he can work and subject to a requirement that he be able to support himself financially, he is a person in a vulnerable position in the Australian labour market,' Mr Hatcher said.

'The description of him as a thief will have gravely affected his reputation and compromised his capacity to obtain future employment.'

Mr Hatcher awarded the cleaner $9,187.20 in wages lost due to his dismissal and he had the right to have his job back.

Mel Gatfield, secretary of United Voice NSW said it was 'outrageous that, in Australia, in 2016, a worker is sacked for having a cup of coffee before his shift'.