A Melbourne man has made a disturbing discovery when unwrapping an M&M's chocolate bar he purchased from a Coles supermarket.

Kyle Rosewarne tucked into his Crispy Mint chocolate block and had eaten four squares before noticing something rather alarming.

As he peeled back the wrapper further, he spotted a dead cockroach embedded inside the confectionery treat.

The disgusted consumer took to Facebook to vent his anger after failing to get a response from the famous chocolate brand.

The chocolate bar that Kyle Rosewarne found containing a dead cockroach. Mars Chocolate Australia claim its 'extremely likely' it entered after the wrapper was opened

Kyle Rosewarne's Facebook post to M&M'S Australia after the chocolate brand failed to respond to his initial approaches

'When I opened the packet yesterday I found an added extra,' he wrote on the social media site.

'To my absolute disgust, there was a dead cockroach inside.'

After his post began to garner significant attention, Mars Chocolate Australia contacted the shell shocked consumer, who was not impressed with their response.

Mr Rosewarne told Daily Mail Australia he received 'your standard corporate apology.'

'They offered me a $20-30 Coles or Woolworths voucher, which I declined.'

The 25-year-old went on to point out the the severity of such a discovery.

'It's not only a health problem, it is a serious ecological concern as well.'

'They're making these in China, so this is more than likely a Chinese cockroach, which could cause serious problems if this isn't the only one. '

A Mars Chocolate Australia spokesperson told Daily Mail Australia that they had 'received a call from a consumer today reporting he had found an insect inside the packaging of one of our chocolate products.'

'We immediately contacted him to request the product and also worked with an entomologist to conduct a preliminary review to determine the insect’s species and origin,' they continued.

'This review has found the insect did not enter the packaging prior to being shipped from our manufacturing facility, as this species does not occur in the region where the product was manufactured.'

'Given each block of chocolate we manufacture undergoes 31 quality checks and safety tests, and microbiological testing before it is packaged and shipped, it is extremely likely it entered the product packaging after it was opened.'

Kyle Rosewarne made the shocking discovery when peeling back the wrapper of his M&M's chocolate bar. He had already eaten four squares before he spotted the bug

Mr Rosewarne however disagrees and questioned the chocolate companies claims.

'If it went in after I ate the initial four pieces then when I went to have more, don't you think it would have crawled out as soon as I picked it up?'

'Why would the thing be dead then?' he also questioned.

He also suggested he will get in touch with the Health Department for advice on the matter.

The new range of bar has only been on the market a matter of weeks and is surely not the introduction confectionery giants Mars had anticipated for the sweet snack.