"There are certain media reports that mathematics paper of CBSE Class XII was leaked. Such reports are increasing doubts in students' minds. I request you to order a fair probe pertaining to reports of paper leak," he said in the letter.
Earlier in the day, Union minister Venkaiah Naidu said the matter "deserves inquiry" and he will convey it to the HRD minister.
Sisodia also said that mathematics is a high-scoring subject and students, who are dreaming to take admission in good colleges, expect more numbers in this subject, but the March 14 paper seemed to have shattered the dreams of such students.
"You should also take an immediate decision to provide grace marks in mathematics paper so that students could recover from hopelessness and appear in other paper without any tension," Sisodia, who also holds education portfolio, said.
The deputy chief minister will visit London to attend a day-long conference on economics.
"He will leave for London tomorrow to attend a conference on Friday," an official said.