An exam board's objectivity has been questioned after it said its aim was to improve pupils' results.
Edexcel, Britain's second largest GCSE and A-level board, said its "philosophy is aimed at increasing student attainment across all grades". The profit-making board made the claim in a letter to Ofqual, the new qualifications regulator, in defence of entry fees for its new A-levels, which have been identified as 35 per cent higher than those of AQA, a rival board.
Professor Alan Smithers, of Buckingham University, said there was a conflict of interest in an exam board both setting grade boundaries and trying to improve results.
He said: "Edexcel is fundamentally misrepresenting the purpose of an examining body, which is to provide accurate and authentic information on achievement. It is not to devise ways of squeezing every last mark out of a system and charging heavily for this."
Critics of England's system of competing exam boards have long complained that it encourages dumbing down, as they fight it out to help schools get good results.
Professor Smithers said Edexcel's statement strengthened the arguments of those who called for there to be just one exam board in order to prevent this happening.
In Edexcel's letter to Ofqual it highlighted its new results analysis service, Results Plus.
The online system allows pupils to find out how they performed in their exams by logging on direct on the same day results are released to schools. It also lets schools carry out question-by-question analysis of how individual students and teachers' whole classes have performed. The board said the system, which is free to users, cost it more than pound;10 million a year.
Stevie Pattison-Dick, Edexcel's head of corporate communications, said there was no conflict of interest. "Edexcel believes it can help more students achieve good GCSE grades," she said. "We believe that giving students and teachers access to detailed, transparent data on examination performance is the right thing to do. Data in this format can then be used in forward planning and to inform teaching and learning - it is this intelligent use of accessible information which leads to raised attainment."
The Examination Officers Association said its members appeared split on the Results Plus system. Some exams officers in schools welcomed the move. "It is helpful to students who are away on results day," one said.
However, several said they did not want pupils to be given their results without a teacher on hand to support them, while others reported technical difficulties.