The trio were found stripped to the bone, with their internal organs neatly placed beside their bodies.
Examinations revealed they had suffered puncture wounds to the neck - consistent with a vicious attack by a panther-like creature.
Experts now believe the animals were devoured by the Wildcat of Woodchester which is already believed to have killed three times this month.
The mutilated bodies of three deer have been found in the past few weeks in countryside near Stroud, Gloucestershire - just 12 miles from where the wallabies were mauled to death.
The wallabies were found only 12 miles apart leading to the belief that it was the same cat
Samples of DNA from the predator's first deer kill on January 4 are currently being tested to confirm whether or not a big cat is behind the killings.
The results are expected to be revealed over the next few days.
But big cat expert Frank Tunbridge is in no doubt over who killed the wallabies and the deer.
Mr Tunbridge, 65, said: 'There could be no creature other than a big cat that could bring down and kill these wallabies.
'The field was surrounded by a 7ft fence and there was no apparent entry signs - so the predator must have leapt over it.
'The killer struck over two nights. The first night he killed two wallabies, stripped one of the carcasses down and hid the other under a pile of leaves and straw.
'Then he came back and killed a third - devouring his further kills. A fourth wallaby appears to have died from a heart attack.
'The wallabies are only about 12 miles from Woodchester so it appears that this could be the same big cat.
'They have all the hallmarks of a panther or puma kill.'
The wallabies, part of a private collection, were found by their devastated owner on January 6 - two days after the apparent first kill by the Wildcat of Woodchester.
The Gloucestershire farmer did not want to divulge his name or location.
But he did release gory pictures of one of the dead wallabies.
The carcass had been ripped open in a similar way to the three roe deers the beast is believed to have slayed.
The first deer had been torn open and was missing its heart, kidneys and liver.
Its snout was also missing - important because big cats clamp their jaws over the mouth, causing death by suffocation.
Experts believe the deer was brought down and devoured by a large and powerful predator such as a puma, jaguar or leopard.
Tufts of the animal’s fur were also found piled by the body - and such predators neatly pluck the hair from the body before shearing their teeth into the flesh.
Another deer carcass was found by a dog walker between Whiteway and Redcomb, near Cirencester - ten miles away - on January 10.
A third roe deer body was found at a development in Cooper’s Edge, near Gloucester, days later.
Dr Robin Allaby, an expert in evolutionary genetics at Warwick University’s School of Life Sciences, is studying samples of DNA taken from the first carcass.
He said: 'I’m prepared to believe in the existence of big cats in the UK and we have a reasonable chance of finding out if it was there.
'We are in the process of studying samples of DNA taken from the deer and if its death was the result of a big cat then we’re hoping it left cheek cells and saliva.'
Is this the culprit? A picture of a large black cat taken in the area.
