New Delhi, June 8 (IANS): The Congress on Monday demanded a judicial inquiry into "cash-for-vote scandal" following airing of an audio tape of a purported telephonic conversation between Andhra Pradesh Chief Minister Chandrababu Naidu and nominated Telangana legislator Elvis Stephenson.

It also sought an inquiry into allegations of snooping against Telangana government.

Party spokesperson Shobha Oza, who addressed the media here, also accused Prime Minister Narendra Modi of being silent on the controversy involving Naidu, who also heads the Telugu Desam Party which is part of National Democratic Alliance central government.

She demanded that Naidu should step down as chief minister following the controversy and there should be an inquiry by a sitting judge of Supreme Court.

Oza alleged that both governments of Telangana and Andhra Pradesh were using "unconstitutional methods" to stay in power.

"There has been allegations of snooping and phone tapping. There should be an inquiry," she said.

The TDP on Monday lodged multiple police complaints against Telangana Chief minister K. Chandrasekhar Rao in Andhra Pradesh, a day after an audio tape of Naidu' purported telephonic conversation surfaced. Alleging that phones of Naidu are being tapped by Telangana government, the TDP government decided to take up the issue with the central government.

Telangana TDP legislator A. Revanth Reddy was arrested by the Anti-Corruption Bureau on May 31 when he was offering Rs.50 lakh to Stephenson to make him vote for the TDP-BJP candidate in the elections to Telangana legislative council.