Monmouthshire MP David Davies has reiterated concerns about financial aspects of the Circuit of Wales plan.
Earlier this week it was revealed the Wales Audit Office has launched an investigation into how a £2m Welsh Government grant handed to the Heads of the Valleys Development Company, along with a £7.35m bank loan guarantee, was used.
Other serious revelations were aired in a BBC Wales Week In Week Out programme broadcast on Tuesday evening which Mr Davies says came to light when documents were leaked to him by a whistleblower.
Mr Davies said he was “very, very concerned” about the information he had been given.
“Essentially Michael Carrick has promised to deliver thousands of jobs to a deprived area of Wales and I would dearly like to see a profitable project employing thousands of people,” he said.
“But that doesn’t mean we should just hand out cash without doing due diligence.”
He added: “I have met Michael Carrick to discuss my concerns and I am very dissatisfied with what I’ve heard.
“That is why I’ve gone to the Audit Office.
“I’m very, very concerned about what’s gone on here.”
A Circuit of Wales spokesman said: “Bank loans supported by the Welsh Government will be paid back fully, with interest, at financial close, something that has been in the public domain since the project began.
“It is important to emphasise that the Welsh Government has a very robust process in place for monitoring this support.
“The Auditor General for Wales has not made contact with the Circuit of Wales team and we will work closely with him and his officers if required to do so.”
He added the organisation was “disappointed” by Davies’ attitude to the project.
“More disappointingly, he seems to be totally out of touch with the majority of his own constituents who stand to benefit from the exposure, awareness, business potential and crucially jobs that the Circuit of Wales will bring to the region,” he said.
“We have encouraged him to focus on the positive nature of the project and to assist us in encouraging and supporting the private investment into this region but to date he has chosen to ignore this.”
The development includes a 3.5-mile racetrack just north of the Rassau Industrial Estate in Ebbw Vale, which is expected to create 6,000 new jobs.
The scheme was rejected by the Welsh Government for a second time in July.