A landlord has been left with a nightmare mess after tenants trashed their $2 million property so badly that professional cleaners have called it “a horror”.

Tenants at the Baulkham Hills house, 31km northwest of the Sydney CBD, dodged inspections for months before finally being evicted, leaving behind a house that’s been left to rot room by room.

WATCH THE VIDEO ABOVE: Rental property left trashed by unruly tenants

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Ashleigh Partsch-Isaako, a professional cleaner brought in to tackle the disaster, said the scene was unlike anything she’d encountered before.

“I need to fully suit up and put on a mask because not only is the smell bad, but we don’t know what’s underneath all this rubbish as well,” she said.

“It was like a horror. It was like I’ve never seen before.”

The house has been left to rot room by room. Credit: 7NEWS

A professional cleaner said the scene was unlike anything she’d encountered before. Credit: 7NEWS

Partsch-Isaako has already completed $4000 worth of work on the home, with the owners — a Tasmanian couple — planning to do the rest of the restoration themselves.

They’re baffled by what their house has turned into compared to the pristine condition they handed it over in.

The home has now almost been restored to a liveable condition after the extensive clean-up effort.

While cases like this are rare, experts warn there’s always a risk when landlords hand over the keys.

“When people invest in property in Australia, they often don’t take into account all of the risks that can be associated,” said Leo Patterson Ross, the CEO of the Tenants’ Union of NSW.

The tenants are also likely to pay the price for their actions.

“The people who’ve been renting this home now might find it difficult to find a new home because there will be this incident on their record,” Ross added.

The tenants are likely to pay the price for their actions. Credit: 7NEWS