The fraud was revealed last October during an episode of Newsnight following investigations by the BBC and CITB.
Thousands of applicants will have to retake their HS&E exam as the CITB announced it is recalling 6,000 tests, and more than 2,000 people are required to reapply for their Site Safety Plus certificate.
In November, CSCS informed all those affected they had one month to register to re-sit their tests and three months to complete them, otherwise their CSCS cards would be no longer valid. At the time CSCS said it "accepts many of the 6,000 cardholders will not have taken part in fraudulent activity, however to retain the support and confidence of the industry and avoid any doubt all the cardholders contacted by CITB will be required to retake the test".
Of the individuals affected, 5,480 failed to register to retake the test. This means their test result is now void. Of those individuals who have already used their test result to obtain a card, 4,615 cards have been revoked. The 553 remaining candidates have until 14 February to successfully take their tests before their cards are also withdrawn.
CSCS chief executive Graham Wren said: "We take assurance that CITB's in-depth analysis was accurate. While we accept that some people have been inconvenienced, we have kept this to a minimum and removed unsafe cards from circulation -¦ While the number of people suspected of fraudulent activity is relatively small, compared to the 400,000 cards issued each year, this type of behaviour has the potential to undermine legitimate employees and harm the reputation of the industry."
In order to receive a new CSCS labourer card, workers must: 1. send their certificate to CITB as proof of their qualification. Accepted qualifications include QCF Level 1 Award, Health and Safety in a Construction Environment; and SCQF Level 4 Award, Health and Safety in a Construction Environment 2. pass the CITB HS&E test - a computer-based multiple choice exam 3. pay a fee of £30.
If workers are not yet qualified or have not previously owned a CSCS card, it is recommended they apply for a provisional card. This allows them to continue working while they complete their qualification training. Provisionals are only valid for six months and are non-renewable.
In a statement issued by CITB on 26 January on the issue of card fraud, delivery and customer engagement director Carl Rhymer said 316 CSCS cards were revoked in 2015, while six individuals have been prosecuted for fraudulent behaviour over the last 24 months.
Rhymer said CITB is "accelerating existing plans to install mandatory CCTV in all testing centres" and is "increasing the number of spot checks of centres to act as a deterrent".
For more information on how to apply for a new card, click here.