More than 2,000 exam papers were combed through for potentially distressing content in the wake of the terror attack in Manchester.
Exam boards took the unprecedented step following the bombing at an Ariana Grande concert in the city to ensure that questions in the papers did not add to anyone's distress.
The move led to at least two exams being changed at the last minute, including one which referred to terrorism, according to the Times Educational Supplement (TES).
Schools were also contacted about other papers, including one that mentioned pop singer Grande, in case they wanted to warn pupils before they sat the exam.
Five people from the North East were among the 22 who died in the suicide bomb attack in Manchester Arena; Chloe Rutherford, 17, and boyfriend Liam Curry, 19, from South Shields; Hartlepool born Jane Tweddle-Taylor, 51; and Philip Tron, 32, and his partner’s daughter Courtney Boyle, 19, from Gateshead.
The attack too place on on May 22 - when GCSE and A-level exams were already taking place.
Seven of the victims were aged under 18, and the youngest was just eight.
Three tragedies occurred within a month this summer, beginning with the Manchester bombing, followed by the terror attack on London Bridge and then the Grenfell Tower fire in west London
It is understood that exam boards began checks immediately after the Manchester attack and continued amid the London tragedies.
In total, 2,144 exam papers that had not been sat by pupils were checked by the four biggest exam boards in England and Wales, the TES reported.
An AQA GCSE religious studies paper, which contained questions which could have been sensitive in light of the terror attack, was changed, along with an Edexcel general studies exam which referenced a source directly related to terrorism.
Edexcel said that given the nature of the source, and the circumstances, it felt that the material "would have been an unnecessary distraction for students".
AQA said it had also contacted a number of schools about two papers - one AS-level French and one A-level French, so they could decide whether to speak to students about them. One included a reference to Grande, and the other contained references to terrorism in the source material.
The exam board said its approach was to "err on the side of caution" to ensure that exam questions did not inadvertently upset any students.
Philip Bridgehouse, AQA customer engagement manager, said: "The events of the summer shocked everyone, so we all felt that it was our duty to make sure that our exams didn't add to anyone's distress. We got straight to work looking at every single exam paper that hadn't yet been sat, and spotting any questions that might upset students.
"It was a massive task to review all our exam papers in a short time, but it was a really important thing to do. The biggest challenge was deciding where to take action, as we wanted to protect students but not cause schools any unnecessary inconvenience."
Welsh exam board WJEC removed a reference to Islamic State in source materials for a media studies GCSE paper, according to the TES.
It has also emerged that the Joint Council for Qualifications (JCQ), which represents the exam boards, has lowered the proportion of a course students must have completed to apply for "special consideration" from 40% to 25%. Pupils can apply for special consideration if they are faced with circumstances that affect their ability to sit exams.
JCQ said that recent tragic events, and a move towards pupils taking all exams at the end of their two-year courses, had led to it reviewing the system.