Chidambaram, in a terse two-page letter to his Swiss counterpart Eveline Widmer Schlumpf, reminded him of the April 2009 declaration adopted by G20 leaders stating the "era of bank secrecy is over."

In a strongly worded letter, he said India might examine further steps like declaring Switzerland a non-cooperative jurisdiction if non-cooperation continues.

Chidambaram said Switzerland has not honoured the terms of the Double Taxation Avoidance Agreement (DTAA) between the two nations, under which information about Indians with accounts in Swiss banks has been sought by the tax authorities.

"Switzerland's refusal to provide information to India and other countries on the grounds that the source of the information requested is based on 'stolen data' means that, in practice, Switzerland still believes in bank secrecy and is therefore not in tune with the modern era," he said in the letter dated March 13.

Recalling the G20 stand that sanctions may be deployed to protect their public finances and financial systems, he said: "If information continues to be denied to India under DTAC (Double Taxation Avoidance Convention), the Government of India will be constrained to take a position in the global forum."

He said India would not hesitate to tell global forums that Switzerland still does not comply with the standards of transparency and that the required legal and regulatory framework is still not in place in Switzerland.

"Further, the Government of India may also have to raise this issue in other multilateral fora such as the G20," he added.

PTI