Bharti Airtel, India's leading telco is facing probe by the Enforcement Directorate (ED) for alleged money laundering, Minister of State for Finance SS Palanimanickam told the Parliament on Tuesday.

"Directorate of Enforcement is investigating cases under the provisions of Prevention of Money Laundering Act, 2002, and Foreign Exchange Management Act, 1999, involving Bharti Airtel Ltd," Palanimanickam said in a written reply to Parliament.

"It may not be in the interest of the ongoing investigations to provide any further details," he added.

In a case filed by ED in February this year, Bharti Airtel and Vodafone Essar were charged with supposedly hoarding excess spectrum. Following this the agency began investigations which focus on the allotment of additional airwaves during the tenure of former communications minister, the late Pramod Mahajan.

The probe was ordered by the Supreme Court and is a part of a sprawling investigation into the affairs of the telecom sector between 2001 and 2008.

Bharti Airtel in a statement said that it has complied with all regulatory norms and that it is cooperating with investigators. The company said that it maintains the highest standards of corporate governance and regulatory compliance and has always complied with all norms," it said in a statement.

"We have already provided all relevant details asked for by the relevant authorities in this matter and will be happy to cooperate further, should the need arise," it further added. Bharti, a third of which is owned by Southeast Asia's top phone company SingTel, operates in 20 countries across Asia and Africa and is the world's fifth biggest mobile phone carrier by subscribers.

Bharti Airtel's stock tumbled 5.1%, immediately after the announcement. However, the scrip recovered and closed at 303.50, down 1.28%.