Prime Minister Malcolm Turnbull has revealed he donated $1.75 million of his own money to the Liberal Party for last year's federal election campaign.

The contribution is believed to be the largest political donation by an individual in Australian history.

Speaking to the ABC's 7.30 program on Wednesday night, Mr Turnbull initially said Australians were more interested in how he spent their money, rather than his own, before he confirmed the amount for the first time.

"In the course of this current financial year, which is why it hasn't been disclosed on the AEC, I contributed $1.75 million. That was the contribution I made," Mr Turnbull said.