New Delhi, Nov 24 (IANS) Corporate lobbyist Nira Radia, whose name figures in the 2G spectrum scam, was questioned by Enforcement Directorate (ED) officials here Wednesday, informed sources said.

Radia arrived at the ED office in the morning in response to a summons. Though she was summoned earlier, she had not appeared then citing "health reasons".

The lobbyist is being questioned on several issues including the possible violation of the Prevention of Money Laundering Act and her firms' alleged links with some of the telecom companies that were allocated 2G spectrum in 2008 by then telecom minister A. Raja, the sources told IANS.

Tapes containing Radia's conversations with Raja, some industrialists and journalists have surfaced. The tapes were submitted as part of the evidence in a public interest litigation regarding the 2G spectrum row in the Supreme Court, the sources said.

A report of the Comptroller and Auditor General (CAG) tabled in parliament Nov 16 had said the 2G spectrum allotment had caused a national loss of several crores of rupees to the public exchequer.

Raja quit as minister due to the 2G spectrum controversy.