Docklands could become a suburb of ghost towers, experts have warned, after an analysis of water use data identified hundreds of apartments suspected of being empty in the CBD precinct.

The study found about 65,000 of 1.5 million properties in prime areas of greater Melbourne could be left empty at time when more than 22,000 Victorians are believed to be homeless.

Left empty: Docklands had the highest number of speculative vacancies of apartments, with 17 per cent consuming no water in 2013. Others used less than 50 litres of water on average each day, leading to assumptions that they were empty or rarely used.

These homes either used no water at all, or less than 50 litres a day over 12 months. A leaky tap is estimated to use up to 55 litres of water a day, according to the report.

The seventh annual Speculative Vacancies study was commissioned by tax-reform group Prosper Australia, which blames the glut in unused homes on investors who hoard properties for long-term profit.