Police in Sydney are treating the death of a British backpacker as a murder-suicide after her body was discovered next to her older Nepalese boyfriend last week.

Amelia Blake was found dead in her Newtown flat, in Sydney, on Friday (12 January) that she shared with her Nepalese boyfriend, who was said to be in his 30's.

The 24-year-old had spent most of her time in Australia working on a farm in Colignan, near Mildurabut, in Victoria. Local reports suggested that she was planning to leave the country altogether.

A post-mortem has been carried out on her body but police do not have all the results although the Daily Telegraph did report that she had suffered multiple injuries.

The Herald Sun reported that their bodies were discovered by the landlord, who had visited their flat to check the post. Police believe the pair had been dead for a few hours when they were found.

The New South Wales police force said Blake's body was heavily bruised and showed signs of severe head injuries.

"Police attended and discovered the bodies of a woman, aged in her 20's, and a man, aged in his 30's," police said while encouraging anyone who may have information about their deaths to come forward.

NSW Police Inspector Chad Deegenaars said according to the Herald Sun: "Up until that point we're still maintaining the crime scene, we're holding that until we get the results of the postmortem," he said.

While Inspector Geoff Olsen said that the force is treating their deaths as "a possible murder-suicide".

Blake had spent Christmas at the farm in Victoria and her Instagram posts indicate she was clearly enjoying her time travelling the country.

"I see my path, but I don't know where it leads. Not knowing where I'm going is what inspires me to travel it", she wrote on the social media website.

Blake's distraught family are heading to Australia and a UK Foreign Office spokesman said consular assistance was being provided.