A freak accident at a Sydney dump has left one man dead and another injured.

Media are reporting the men became trapped under tonnes of landfill during a workplace incident at Eastern Creek at about midday Monday.

Rescuers tried frantically to dig out the men by hand but it was too late for one of victims whose age is unknown at this stage.

One man has been killed and another has been injured, after being crushed under tonnes of debris at a landfill site in Sydney's west. #9News pic.twitter.com/tP4uVVAuPb

— 9News Sydney (@9NewsSyd) May 27, 2019

The second man in his 30s was rushed to Westmead Hospital with abdominal and shoulder injuries, while the other remains trapped. His condition is not yet known, a NSW Ambulance spokeswoman said.

The cause of the accident will be investigated however media reports suggest the pair were hit by a heavy vehicle and covered in the debris it was pushing.

The Eastern Creek facility if a former quarry that was transformed into a construction, demolition and commercial waste recycling and recovery centre and landfill known as Genesis.

The facility is licensed to accept 2 million tonnes per year of construction and demolition waste enabling it to capture a significant portion of the waste recycling market in the Sydney region, according to the business website.

More to come.