Jonathan Palmer, chairman of AMRCO which represents 17 UK race tracks, said: "The UK circuit industry welcomes innovation and investment, however history and experience suggest that an investment of this magnitude in a motor racing circuit will never produce a return for investors.
"It is a real concern that this will turn into a white elephant at the expense of much needed public funds, and we hope this project will now be subject to careful scrutiny by Welsh government inspectors and the Wales Audit Office."
In response, a spokesman for the Circuit of Wales said:"It's no surprise that we are seen as a competitive threat to many of the existing sites that we have in the UK.
"Over the course of the last three years we have met with senior management of 11 of the 17 circuit owners, many of whom have input into our business plan and several operators who have expressed interest in providing services to the circuit."
Welsh government inspectors are still considering whether to review the project.