Business has been booming at Olympic Training Services, now known as OTS (Wales) Ltd, despite receiving an overall grade 5, the lowest possible score, from Estyn in a damning 2005 inspection.
But, from 2008, all work-based training providers must score at least grade 3 overall before being awarded a contract.
In October, the Assembly government decided not to extend a contract with OTS (Wales) Ltd, "following their failure to address shortcomings in quality". A spokesperson said another training provider had now been found.
Figures obtained by TES Cymru show that OTS (Wales) Ltd, which also provides courses for the care of the elderly, was given more than pound;1.2 million worth of business in 20045 by the former post-16 funding body ELWa - treble the amount of three years previously.
But Estyn inspectors found little improvement in the firm's standards on re-inspection in April 2006, despite the company attracting 150 new customers from Wales and England since the report.
One area that had improved was learners' achievements, but it was still rated at a below par grade 4.
ELWa first did business with Olympic Training Services Ltd in 2002-3.
TES Cymru has discovered that, in July 2003, Olympic Training Services Ltd changed its name to Arrow Training Ltd, which, in September 2004, became subject to a winding up order and is now in liquidation.
ELWa signed a new contract with OTS (Wales) Ltd in August 2004 and only became aware that Olympic had changed its name to Arrow "after the event".
An Assembly spokesman said the change "had not affected the delivery of training" and that learners had been transferred to an alternative provider. "There has been no loss of public funding," he said.
Recently, the Assembly's audit committee condemned standards of financial control among Wales's 121 training providers. It said that all providers must have clear minimum standards when the new contracting phase starts in 2007, and that inadequate systems of control "cannot be divorced from performance". It was also concerned by relatively poor learner attainment.
Eddie Hewett, OTS (Wales) Ltd director, also a director at Arrow, declined to comment on why that company had gone into liquidation, but said he had been "disappointed" by Estyn's unfavourable re-inspection. "Things are improving," he said.