Allegations "spies" were sent to a school to pose as parents and pick up information for a rival institution have been defended as "nothing unusual".
Senior education officers at Cognita UK, a group run by ex-Ofsted chief Sir Chris Woodhead, were sent to St Michael's School in Llanelli, Wales, to take part in "commercial espionage", it emerged on Sunday.
Staff at Cognita, a multi-million pound private school chain, were "handed scripts" by the UK marketing director Nicole Louis in order to obtain information. Cognita's Ffynone House school in Swansea competes with St Michael's, which charges more than £10,000 annually in fees.
But Louis defended the action on Wednesday, saying: "The allegations form the basis of an employer tribunal which will take place next month.
"Cognita will robustly defend all of the allegations referenced within the article and in the specific matter regarding St Michael's School in Llanelli, having taken expert advice, we are certain that we have not done anything wrong or unusual in organising the 'mystery shopping' trips."
St Michael's head Daniel Sheehan, said he was "shocked" at the allegations, which first appeared in the Observer on Sunday at the weekend.
"Though it could be seen as a compliment that the ex-Ofsted chief inspector's multi-million pound organisation thought that they could learn something from St Michael's remarkable success," he told local Welsh paper the Llanelli Star.
Woodhead, who runs Cognita, said he would "robustly" defend the allegations, although would not elaborate further.
The Department for Education, who is currently investigating the claims, also denied to comment.
Ffynone House has since been transferred back to its previous owners amid questions over the school's financial viability, according to the Llanelli Star.