IndiGo Airlines (6E, Delhi International) co-founder Rahul Bhatia filed a case in the Maryland District Court in the United States seeking an order to retrieve the correspondence of Anupam Khanna, an independent director on the carrier's board, the Times News Network has reported.

Bhatia and his investment vehicle InterGlobe Enterprises (IGE), who own a 38% stake in the Indian LCC, have alleged that Khanna acted in coordination with Rakesh Gangwal, IndiGo's other co-founder, a 37% stakeholder, and a party to a public argument with Bhatia.

"In light of the evidence of cooperation between Khanna and Gangwal, the petitioners believe that Khanna is likely to be in possession, custody or control of documents and communications concerning the actions taken by Gangwal to the detriment of the company," IGE said.

Bhatia's group is seeking to obtain documents to use them in an ongoing arbitration in London.

In its filing in the Maryland court, IGE argued that communications between Khanna and Gangwal prove cooperation in an effort to reduce IGE's influence over the carrier in a breach of the shareholders' agreement.

"Khanna has historically aligned himself with Gangwal, and petitioners believe that he is 'acting in concert with Gangwal in a clandestine manner ... notwithstanding his position as an independent director on the board," the filing said.

Gangwal is a US citizen while Khanna is a resident in Maryland.

The two co-founders have been involved in a public argument over the last few months, tossing accusations of breaching corporate governance standards at each other.

In July, Gangwal has sent a letter to the Securities and Exchange Board of India (SEBI) asking the regulator to probe alleged corporate governance shortcomings at the LCC. In it, he accused Bhatia of enjoying and abusing "unusual controlling rights over IndiGo". Bhatia's group responded by saying that the company was well run, financially sound, and managed by competent leadership, adding that no abuse of rights had occurred.

In early October, Bhatia and IGE filed for arbitration in the London Court of International Arbitration. Gangwal has yet to respond to this request.