The comments by a former official of CAG over the report on 2G spectrum allocation today kicked up a row with Congress President Sonia Gandhi suggesting that BJP had been exposed while the government demanded answers from Parliament's PAC chief M M Joshi over his alleged role.

Joshi, a senior BJP leader, rejected allegations by R P Singh, former Director General, Posts and Telecommunications in CAG, that he had tried to influence the outcome of the 2G report and questioned why the official had not spoken about it in Public Accounts Committee (PAC) when he appeared before it.

"Yes, certainly I think so," said Gandhi when reporters here asked whether BJP had been "exposed" by Singh's comments. Information and Broadcasting Minister Manish Tewari said Joshi as also CAG should clear the air on the issue.