"The Department of Commerce is working to build up a case of WTO violations by US resulting from the implementation of the visa fee hike," an official told PTI.
He said the discrimination was the result of the US Border Security Act of 2010. India has been raising its concern for the last 18 months.
The law, also known as the James Zadroga Act, substantially increased the fees for H1B and L1 categories of visas for applicants which employ more than 50 persons in the US or have more than 50 per cent their employees admitted on non-immigrant visas (the 50:50 rule).
The official said both the Indian and the US service suppliers perform similar services but are "being treated differently...resulting in formally and substantively different treatment. This results in violations of the specific commitments of the US under WTO."
Sources said during the Congressional debate in the US, it was widely acknowledged that four top Indian companies - TCS, Infosys, Wipro and Mahindra Satyam - were to pay significantly higher fees. However, the large American high-tech corporations which may bring higher numbers of skilled immigrants into the US would not be affected, since vast majority of their work force is made of Americans.
"It is the sovereign right of any country to hike visa fee, but the US move is mainly against the Indian IT companies. The law discriminates between an American and Indian company. This is a breach of national treatment and most favoured nation status," a Commerce Ministry official said.
Although India has time and again raised its concern no satisfactory response has been received, he said.
"Rather the US has continued to impose several new protectionist measures, including increasing the period of applicability of the enhanced visa fees under the James Zadroga Act," he said.