(ABC) - The wine equalisation tax or "WET" is a value-based tax system, designed to compensate some grape growers for other tax payments. But it's recently come under the spotlight of producers, some of whom say it's not making Australian wines competitive on the world market. South Australian grower Dudley Brown says growers are being ripped off by middle men, and the tax office is reportedly conducting audits to find out. Dudley Brown is a Californian who moved to Australia to grow wine.