It is a McDonald's burger allegedly bought in 1995, and had been kept in an Australian shed for years. Surprisingly, this 24-year-old burger has never decomposed. /VCG Photo

Casey Dean, 39, and Eduards Nits, 38, said that they ordered the Quarter Pounder with cheese from a McDonald's outlet in Adelaide as teenagers, and they have hung onto it ever since. /VCG Photo

Although the burger has shrunk a little from its original size, its shape remains intact. It doesn't smell and there are no signs of mould. /VCG Photo

"The reason why our burgers sometimes don't go mouldy when left out at room temperature, in a dry environment, is that once the food is cooked there isn't enough moisture to support bacterial growth to break it down," a McDonald's spokesperson said. /VCG Photo