Delhi customs has issued summons to Reliance Transport and Travels Pvt Ltd (RTT), an Anil Ambani company, in connection with the import of a Bombardier Global 5000 16-seater aircraft. Sources close to the company said it had "complied with all rules and regulations" and had also given customs a detailed reply with documents.

Earlier this month, Mumbai customs had seized an Airbus A 319 and a Falcon 900 owned by the Mukesh Ambani group for alleged duty evasion. Till now, about 10 aircraft belonging to various corporate entities have been seized and subsequently released on bank guarantees. A senior customs official said some business houses had taken "advantage" of the duty exemption announced last year on import of aircraft meant for chartered flights. But it was found that many of these aircraft were actually being used for personal purposes.

Aircraft imported for private purposes attract 28% duty as against zero duty for scheduled and non-scheduled operators (regular and charter airlines). Over 65 of the 86 operators with NSO permits are said to be under the scanner. Customs have been checking pilots’ logbooks to counter the owners' claims that aircraft are being used for charter.

The Bombardier for which Delhi customs has issued a summons was imported this year at a cost of Rs 200 crore. It involves a duty of about Rs 50 crore if it is found that it was being used as a non-charter airplane (an agency report put the cost at Rs 150 crore and duty at Rs 37 crore).

A spokesperson for Anil Ambani insisted that the import and its subsequent use met with all rules and regulations. He said Delhi customs had issued summons to RTT which is a valid NSO permit holder and RTT had responded and given "full and comprehensive documentation" regarding the aircraft.

"RTT informed customs that it had complied with all rules and regulations. RTT operates for passengers and all flights are paid for and applicable taxes like TDS and service taxes have been paid to the statutory authorities," he added.

"RTT also offered voluntarily, to deposit a bank guarantee or bond with customs. However, due to the procedural formalities of customs, RTT was informed that the bond could not be accepted unless a seizure memo was issued and executed," the spokesperson said.