­PESHAWAR - Pakistan Tehreek-i-Insaaf (PTI) Chairman Imran Khan appeared before the National Accountability Bureau (NAB) at the bureau's Khyber Pakhtunkhwa (KP) office in Peshawar on Tuesday in a case pertaining to alleged misuse of provincial government's helicopters during his party's past tenure in KP.

A questionnaire prepared by NAB with 15 queries was handed to Khan and his lawyers. The questionnaire needs to be completed within 15 days, according to NAB officials. The officials said that Imran Khan was "interrogated inside the NAB office for more than one hour".

Former chief minister of KP Pervaiz Khattak and former speaker of provincial assembly Asad Qaiser accompanied Imran to the NAB Peshawar office.

Strict security measures were put in place around NAB's Peshawar office. Security was also tightened in Hayatabad and surrounding areas.

Certain government officials and Khattak have already appeared before the joint investigation team in the same inquiry. Earlier, the NAB had issued a notice to Imran on July 11, summoning him to appear before a joint investigation team on July 18.

However, due to Khan’s involvement in elections, his law firm Babar Awan and Associates had submitted an application asking for more time which was accepted.

In February, after taking notice of the helicopter issue when it was highlighted by print and electronic media, NAB had taken its first action against Khan and KP Chief Minister Pervaiz Khattak for allegedly misusing official helicopters for private visits. NAB Chairman Justice (Retd) Javed Iqbal had directed the bureau’s KP director general to conduct an inquiry against CM Khattak and Khan over 74-hours unofficial use of two government helicopters — Mi-17 and Ecureuil — by misusing authority.

The KP government, however, [had denied that Khan used any official helicopter] for his private and personal use.

A spokesperson of the PTI-led provincial government had said that since 2013, the government had not used helicopters for any purpose other than official business. The bureau had said the PTI should have paid the KP government Rs11.1 million for the helicopters but official documents only mention a payment of Rs2.1 million.

The NAB alleged there was documentary evidence that Khan had paid Rs2.1 million for two helicopters belonging to KP government — an Mi-171 and an Ecureuil — for a total of 74 hours, which amounts to Rs28,000 spent for every hour the helicopters were used.

In a statement, the PTI had welcomed NAB’s investigation into alleged misuse of helicopter and stated that it always supports fair investigations.