The Government’s leading adviser on academies also works for a headhunting firm which has been working with three of the new schools, The TES has discovered.

Sir Bruce Liddington, who was appointed by the Department for Education and Employment in 2000 to give professional advice on the development of academy projects, is also a freelance associate for Veredus Executive Resourcing.

Veredus has been selected to find senior staff, including headteachers, for three London schools: Capital City academy, the Greig academy and Harefield academy.

There is no suggestion that Sir Bruce was involved in, or in any way influenced, the selection of Veredus for contracts with any of the academies.

He is a self-employed consultant, and an employee neither of the Department for Education and Skills nor of Veredus. However, the revelation will focus attention on the need to keep the new schools at arms’ length from companies supplying services.

John Bangs, head of education at the National Union of Teachers, said: “If there’s going to be any confidence in the Government’s policies, there really has to be a clear distinction between those who are responsible for the interpretation of the policy and any connections that they have outside of Government.”

As The TES disclosed earlier this month, two other academies, West London Academy, Ealing, and King’s Academy, Middlesbrough, have made payments for support services to companies in which their sponsors have major interests.

Sir Bruce is a former headteacher who was knighted in 2000 for turning around Northampton school for boys, which had been threatened with closure. He was appointed by the DfES as one of a small team of advisers on the new schools.

He had special responsibility for Capital City Academy, in Brent, north London, acting as project manager in its transition from the former Willesden high school. He now spends most of his time working for the department on academies.For the past year, he has also been a consultant at Veredus, working 12 days annually, for which he is paid by the day, giving advice on “general educational matters”.

Veredus, a part of the Capita group, has described itself in advertising as the “UK’s top head-hunters”, recruiting senior managers to posts across the public and private sectors.

Sir Bruce is also chairman of the East Midlands Leadership Centre, a branch of the National College for School Leadership. The centre appointed Veredus earlier this year to recruit its new commercial director.

However, Jan Marshall, the centre’s chief executive, said Sir Bruce had declared his interest and had played no part in the process of deciding which firm to use. The recruitment process had been put out to tender to two or three firms, she said.

A DfES spokeswoman said: “Sir Bruce Liddington is employed with full regard to civil service employment regulations which ensure there is absolutely no conflict of interest.”

A spokeswoman for the Capita Group said: “There is no conflict of interest and to claim otherwise is nonsense.”

Sir Bruce said that the charitable trusts which ran academies took control over decisions such as which recruitment firm to employ, and that he could have no input in that process.

As a consultant, it was natural that he would obtain work from more than one source. He said: “I’m a totally self-employed person. There is absolutely no conflict of interest.”

The DfES is believed to pay advisers between pound;500 to pound;1,500 per day.