Circuit of Wales could have created 3,300 jobs, consultants said
Up to 3,300 jobs could have been created by a £433m motor-racing track, hotel and business park in Blaenau Gwent if the cancelled project had gone ahead as planned, consultants said.
The estimate is lower than that of the Circuit of Wales's developers, but higher than figures cited by ministers when they walked away from the scheme.
Plaid Cymru has accused the Welsh Government of downplaying the benefits.
Ministers said it was misleading of Plaid to "cherry pick" draft data.
A leaked report by consultants Regeneris, commissioned by the Welsh Government, says building work could have created another 4,630 jobs during the construction phase - far fewer than the 11,773 estimated by the developers.
Although the project would have been built with private cash, the developers wanted the Welsh Government to guarantee half the cost of phase one of the Circuit of Wales, which included the racing track itself.
The guarantee would have meant the taxpayer faced a bill if the business failed, but ministers decided in June there was a risk that all the debts of the project would end up on the government's books.
At the time, the Welsh Government said its analysis found only around 100 full-time jobs would be created in the first phase of the circuit, with another 500 thanks to money spent by visitors.
The 3,300 jobs figure includes other schemes it was hoped would be attracted to the site near Ebbw Vale as part of the later second phase, including a hotel and technology park.
The consultants' report was written as part of the Welsh Government's analysis of the plans, known as due diligence.
It says some of the developers' estimates are "overestimated", a prediction of temporary jobs is "misleading" and the circuit's plans include "an element of double counting" of jobs created.
However, Plaid Cymru economy spokesman Adam Price said: "It's clear to me that the government used the lowest figures in the report in order to spare its blushes at pulling the plug on a project with significant potential in which it had invested millions."
Despite eventually rejecting it, the Welsh Government had given the Circuit of Wales backers more than £9m to develop the plans.
In April the auditor general criticised "significant shortcomings" in the way that money was handed over.
A Welsh Government spokesman said: "It is Adam Price's decision to cherry pick tables from draft and unpublished reports and present them in a mischievous way that is actually misleading.
"We will be publishing the correct, full and final version of the summary due diligence reports very shortly so they can be considered properly and in their entirety."
The Conservatives said Mr Skates' department was "in a state of chaos".
Welsh Conservative leader Andrew RT Davies said: "Sadly, it's becoming clearer by the day that a lack of faith from Welsh Government and concerns over its backers may have ultimately cost the region significant jobs."