In his letter, Sinha said any hesitation on his part to appear before JPC will prove that he has "something to hide".
Sinha pointed out that when Parliament's Public Accounts Committee was examining the CAG report on the 2G scam, the Prime Minister had publicly offered to appear before it to enable the committee reach the "right conclusions".
He claimed that in his communications to the JPC, Raja has levelled "serious allegations" against the Prime Minister and Finance Minister P Chidambaram.
"I think it is in your own personal interest to appear before the JPC and clear your name. You may also suggest the Finance Minister to make a similar offer," he wrote.
Sinha asked the Prime Minister to request JPC Chairman P C Chacko to call Raja as a witness before the committee.