India's federal police on Saturday conducted searches at Vodafone's Indian unit and Bharti Airtel's offices seeking details on spectrum allocation by the government to operators between 2001-02.
The searches were in regard to possible irregularities in allotting spectrum during the previous government led by the Bharatiya Janata Party (BJP), now in opposition, Central Bureau of Investigation's (CBI) spokeswoman, Dharini Mishra told Reuters.
"All our documents are in complete compliance with the governing laws and regulations. Vodafone India is completely co-operating with the officials and will provide them all the required details as part of their checks," Vodafone said in a statement.
The CBI conducted raids at Vodafone's Mumbai and New Delhi offices and Bharti Airtel's office in Gurgaon, near New Delhi.
"We would like to categorically state that all the spectrum allotted to us from time to time has been strictly as per the stated government policy," Bharti Airtel's spokesman said in a statement.
"We are providing all details and correspondence to the authorities and shall provide complete support as needed in the matter," Bharti Airtel's spokesperson said.
India's Congress party-led government has been rocked by a series of corruption scandals that sparked massive street protests by anti-graft activists, sent prominent politicians to trial and undermined investor confidence in the Asian giant.
The biggest case involves the trial of business executives and the former telecoms minister, who is accused of taking bribes to favor some firms which wanted to buy mobile phone licences. A state auditor has said the under-selling of licences for kickbacks may have cost India $39 billion in revenue.
Saturday's searches could give the Congress party ammunition to fight back against the main opposition BJP's attacks against the government. Shouting matches and walkouts shut down parliament on a near daily basis for much of the year.
The BJP repeated past accusations that the CBI was under the tacit control of the Congress party. A BJP spokesman said the searches were carried out to deflect scrutiny away from the government's own corruption scandals.
"Now they are raking up this issue just to divert the attention," Prakash Javadekar, a BJP spokesperson told a press conference.
Controversial anti-corruption legislation will likely top the agenda when parliament reconvenes on Tuesday.
(Reporting by Siddesh Mayenkar in Mumbai & Matthias Williams in New Delhi, Editing by Jonathan Thatcher)