PHOTO: Investors can claim 2.5 per cent of construction costs per year. Photo: Robert Shakespeare.

Everyday Australians could be throwing away the opportunity to purchase an investment property, with new data revealing three out of five people aren’t aware of one of the most lucrative tax deductions investors use to help make a purchase affordable.

According to a recent survey by online lender State Custodians, 61 per cent of respondents don’t know that mortgage interest payments on an investment property are tax deductible.