A husband and wife duo are behind bars after a long-running investigation targeted them as ringleaders of a scheme that has been issuing fraudulent construction industry trade qualifications to unqualified people for a fee since at least 2015.

Cameron Russell, 55 and wife Fay, 52, were extradited to NSW earlier this month before they were charged over the scheme, which allegedly issued fake certificates in trades such as building, electrotechnology, gas fittings, air-conditioning and refrigeration.

Cameron and Fay Russell. Credit:Facebook

It is estimated hundreds of fake qualifications may have been issued through the scheme, raising concerns about the potential number of unqualified people currently working on construction sites around Sydney.

The couple, believed to be the ringleaders of the scheme, were among nine people arrested and charged over the alleged construction industry fraud, which has been under investigation by the Organised Crime Squad’s Money Laundering Unit and the NSW Crime Commission since June.