Two men aged 29 and 32 have been arrested over the Maths A-level leak, the Metropolitan Police has said.
Both men, who were arrested on suspicion of theft, were detained for questioning but have since been released.
Earlier this month, police were called in after an Edexcel A-level Maths paper surfaced online ahead of the exam, in what the exam board called a "serious breach of security".
Pictures of two questions were posted from a Twitter account - which has since been deleted - the day before the exam, with the details scribbled out. An accompanying message invited students to get in touch via a direct message “if you want tomorrow’s A-level maths, stats and mechanics paper 3 exam”.
Others claimed that the entire paper had been leaked and was circulating in group message conversations on the morning of the exam.
It is the third consecutive year that questions from the exam board’s Maths A-level papers were leaked before the exam.
Pearson, which owns Edexcel, has issued a statement reassuring students that “no-one will be advantaged or disadvantaged” as a result of the leak.
Roughly 60,000 students took EdExcel’s Maths A-level, which consisted of three exam papers spread over two weeks earlier this month.
Sharon Hague, a senior vice president at Pearson, said: “We understand students are rightfully concerned and want a fair playing field.
“The actions we have taken to strengthen our security processes have enabled us, in conjunction with the police, to quickly identify those who we believe were involved in the breach and to take swift and immediate action.
“We are systematically working through all leads and, as we continue to investigate the suspects, this will enable us to further hone in on anyone that has gained an advantage, and take action accordingly. Our key priority is ensuring no students are disadvantaged in any way.”
A Met Police spokesman said: "On Sunday, 16 June, an allegation was made by an examination board that a 2019 ‘A Level’ Maths paper had been leaked by a third party on social media.
"Officers recorded the allegation as an offence under the Theft Act 1968. On Monday, 24 June, two men aged 29 and 32, were arrested on suspicion of theft and taken into custody. They have since been released under investigation. Enquiries continue."