Ofqual is set to fine an exam board £125,000 after GCSE computing controlled assessments included questions with answers that appeared in textbooks.
The exams regulator, which revealed its intention to fine OCR today, says the mistakes were likely to have given an "unfair advantage" to candidates who had access to the publications.
Ofqual said it would have fined OCR more had it not given undertakings to prevent the incidents happening again.
The exam board admitted failing to comply with 15 of Ofqual's general conditions of recognition and “has given an undertaking setting out how it will prevent any recurrence of the incidents”.
In April 2016, OCR told Ofqual that a textbook OCR Computing for GCSE "appeared to include a solution" to parts of a controlled assessment task sat by pupils in 2016.
The following month, it flagged up two stories on social media "which referred to candidates for GCSE Computing finding the answers to the controlled assessment tasks in the computing textbook".
Two experts hired by Ofqual concluded that the code set out in the computing textbook was "identical to the ‘mystery code’ forming part of the controlled assessment", and that pupils who had access to the text book would have been "advantaged".
In August, the exam board told Ofqual about a similar problem with another textbook, this time for computer science and published in 2016, which included material that would have helped candidates sitting a controlled assessment task for GCSE Computing in the following year.
In its notice of its intention to fine OCR, Ofqual said: "The incidents concerning the textbooks appear to have occurred because the textbook authors were the Principal Moderators for Unit A452 and A453 and, in that capacity, had been instructed to devise the 2016 and 2017 controlled assessment tasks for GCSE Computing."
It says they had completed assessor declaration of interest forms for OCR, but "OCR has admitted that it did not have a clear or sufficient process in place to follow-up declarations made by persons who had been invited to write assessment materials".
The notice says: "The breach of confidentiality in respect of the textbooks is likely to have conveyed an unfair advantage on candidates with access to those textbooks, in circumstances where over 55,000 textbooks had been sold."
The notice also highlights 72 cases where suspected malpractice in controlled assessments in 2015 had not been referred for investigation, and inconsistency in guidance for schools about whether GCSE Computing controlled assessments should be held under ‘formal supervision’ by teachers, or 'medium control'.
Ofqual said OCR had also submitted an annual statement to Ofqual "which was not accurate."
The notice says OCR had spent over £300,000 addressing and resolving the incidents, and given a "regulatory undertaking" setting out the measures it will take to prevent any recurrence of the incidents.
Ofqual gave notice that it intends to fine OCR £125,000.
OCR apologised for "a combination of issues relating to the old GCSE in Computing that has led to Ofqual’s regulatory action".
It added: "Challenges around coursework malpractice in the subject are well known but we recognise there were a number of regulatory areas in which we failed to meet the standards rightly expected of us and we breached conditions. Importantly, these had no impact on students or on exam results.
"We have invested heavily and worked extensively to put things right, and have changed our processes in response."