He cited the correspondence between former Telecom Minister A Raja and the Prime Minister relating to the 2G spectrum, which has been annexed with chargesheet, for demanding that Singh be made a witness.
"Central Bureau of Investigation is producing letters of Raja and the Prime Minister as evidence.
"They should have made the Prime Minister a witness in the case," advocate Majid Memon, appearing for Balwa, told Special CBI Judge O P Saini while arguing his bail plea.
Memon along with advocate Vijay Agrawal said that CBI has produced letters written by Raja to Prime Minister and his response as a evidence in the case.
Memon said that Raja was in touch with the Prime Minister and he regularly apprised him about the development in the department of telecommunication.
They said the agency, in its first chargesheet, has said that Raja misled the Prime Minister but instead of CBI, the PM should tell this.
"CBI is saying Raja misled the PM. If it is so, then it should be the PM who should say this, not the CBI," Agrawal said.
During the arguments, Memon also pointed out to the letters written by Raja to the Prime Minister on November 2, 2007 and the subsequent letters to Raja from the Prime Minister.
He said when Swan Telecom applied for the licenses, neither Raja was the telecom minister nor his personal secretary R K Chandolia, who has named as accused in the chargesheet, was there.
Pressing for Balwa's bail, Memon said that the offence under which his client has been charged does not fall under the category of grave offences punishable upto life imprisonment or death penalty.
He alleged that CBI is enjoying that Balwa is behind the bars.
CBI says that Balwa cannot come out of jail as if they are enjoying my (Balwa's) sufferings behind the bars," he said.
"CBI may be feeling a sense of shame if they will not oppose the bail plea in such a high magnitude case and so they are opposing it."