The inquiry is being led by Sir John Dunford and was launched last year. It has already taken evidence from a range of educational organisations, leaders and government bodies.
The new call for evidence is aimed at those involved in and working with the exam system and the deadline is March 18.
Sir John said: “Public confidence in the integrity of the examination system is paramount and there is more that can be done to reduce malpractice. I hope that many of those involved in the exam system will respond to the call for evidence.
“The Commission will make recommendations to all stakeholders in the examination system, including the government, the regulators and awarding bodies on improvements that can be made to reduce and deter malpractice.”
Visit http://bit.ly/2GSGm67 or email Commission@jcq.org.uk