Exam board Edexcel has insisted it is "certain" the standard of its qualifications are on a par with its rivals after an internal review of claims that they are easier.
It said there is no evidence to support chief examiner Steph Warren's comments that its GCSE geography tests are not as difficult as those from other exam boards.
She was recorded by The Daily Telegraph describing her disbelief that the test had been cleared by exam regulator Ofqual.
Speaking at an Edexcel seminar in Birmingham last month, she said teachers should choose their exam because "you don't have to teach a lot".
In a statement released on Sunday night, Edexcel said it had analysed data from all five awarding bodies for GCSE geography, history and English and found that candidates are "no more or less likely" to achieve certain grades with its exams compared with other boards.
It said that it had also assessed the "breadth and depth of the exam specifications" and is confident they are of the appropriate standard set by Ofqual.
"As a result of this analysis, we are certain that Edexcel's qualifications are of the same standard as those of the other major awarding bodies," it said.
It said Ms Warren, who was suspended last week, was one of 106 chief examiners for Edexcel. "We are confident that the personal opinions expressed by Ms Warren are not supported by the evidence," it added.
Two other examiners with the Welsh exam board WJEC have also been suspended, over claims that teachers were given detailed advice on forthcoming exam questions and how students could score higher marks.
Ofqual has warned that exam boards could be forced to re-write next year's GCSE and A-level papers if it is found that teachers were given unfair advice on how to boost results.