The headteacher of a high profile multi-academy trust, which won plaudits from former prime minister David Cameron and his then education secretary Michael Gove, has been banned from teaching indefinitely.

Liam Nolan, who was executive headteacher and chief executive of the now defunct Perry Beeches academy trust in Birmingham, was found guilty of “unacceptable professional conduct” after a hearing before the Teaching Regulation Agency (TRA).

Acknowledging Nolan’s contribution to the teaching profession, the TRA report said he should be allowed to apply to have the prohibition order lifted after a minimum two-year period, which would give him time to “reflect on his failings”.

The prohibition order against Nolan is the latest chapter in the demise of the Perry Beeches academy chain, which was stripped of its five schools after an investigation revealed financial irregularities at the trust, including third-party payments to Nolan, on top of his £120,000 salary as executive headteacher.

The Education Funding Agency investigation found nearly £1.3m in payments without contracts to a third-party supplier, a private company called Nexus. That company also subcontracted to a company named Liam Nolan Ltd, paying Nolan a second salary for his role as chief executive officer of the trust.

At the time, critics of the government’s academies policy, which takes schools out of local authority control, said the case should ring alarm bells over the accountability and financial management of academy chains and the government’s ability to police the system.

The TRA hearing found that Nolan failed to comply with recognised procedures and principles in relation to management of public funds and was in breach of the academies’ financial handbook, which sets out the financial management, control and reporting requirements for all academy trusts.

“Mr Nolan stated in his evidence that he was under pressure in developing the Perry Beeches schools and that it was against this background that he made what he described as mistakes,” the TRA report said. “However, the panel was not convinced this justified his lack of integrity in managing public finances. Although Mr Nolan apologised for some of his failings as accounting officer, there did not appear to be sufficient insight into the seriousness of those failings or his responsibility in that post.”

Cameron opened one of Perry Beeches’ new free schools in 2013, when the then prime minister praised the “brilliant team” at the trust. In 2012, Nolan addressed the Conservative party conference and appeared on stage with the then education secretary Michael Gove, who described Nolan as “wonderful”.