TORONTO - Ontario's health minister says the treatment of so-called medical tourists at a few hospitals in the province generates millions of dollars of revenue for the health system.

Eric Hoskins says no public money can be used to care for these patients and any revenue generated -- which he estimates could be up to $20 million per year -- must be reinvested to benefit Ontario patients.

He says only a small number of hospitals in the province treat medical tourists and the proportion compared to Ontario patients is quite small.

The Registered Nurses' Association of Ontario is urging Hoskins to ban medical tourism, aside from humanitarian cases, saying the practice promotes queue jumping.

But Hoskins says that's not the case, and that international patient revenue could allow a hospital to open more hospital beds or hire more nurses.

The Ministry of Health and Long-Term Care is currently reviewing the practice to ensure that Ontario patients are coming first.