Islamabad Pakistan Tehreek-e-Insaaf (PTI) chairman Imran Khan appeared before the National Accountability Bureau (NAB) at its office in Peshawar on Tuesday in a case related to alleged misuse of the Khyber-Pakhtunkhwa government’s helicopters.Khan has been accused of illegally using Mi-17 and an Ecureuil helicopters belonging to the provincial government for 74 hours, causing losses of Rs 2.1 million to the national exchequer. The PTI was in power in the province till recently.He had been summoned by the anti-corruption body on July 18, but had sought more time to appear due to his busy schedule for campaigning for the July 25 general election. He submitted an application to the NAB through his counsel Babar Awan, seeking another date to appear. Awan had also filed an appeal, requesting NAB to fix the case after the general elections, “preferably on August 7”. A questionnaire with 15 queries prepared by NAB was handed over to Khan and his lawyers on Tuesday. The questionnaire needs to be answered within 15 days, NAB officials said. They said Khan was “interrogated inside the NAB office in connection to the case for more than one hour”.In February, after taking notice of the issue when it was highlighted by the print and electronic media, NAB had taken its first action against Khan and former Khyber-Pakhtunkhwa chief minister Pervez Khattak for allegedly misusing official aircraft for private visits.NAB chairman Javed Iqbal directed the bureau’s provincial director general to conduct an inquiry against Khattak and Khan over the unofficial use of two government helicopters.The provincial government, however, said Khan had not used any official helicopter for private and personal trips. A spokesperson of the PTI-led provincial government had said that since 2013, authorities had not used helicopters for any purpose other than official business.