PESHAWAR: The National Accountability Bureau (NAB), Khyber Pakhtunkhwa, on Wednesday arrested a contractor and a sub-engineer for their alleged anomalies in development schemes in Swat. NAB arrested Muhammad Aimal Khan, a contractor, who is son of former MNA Muzaffarul Mulk, and Nisar Aziz, sub-engineer of Pakistan Public Works Department, Batkhela, for allegedly causing a colossal loss to the public exchequer worth millions of rupees through ghost and substandard schemes in NA-29 Mingora, Swat. The NAB KP has claimed in a communiqué that Pakistan Public Works Department (PWD), Batkhela Division, awarded various development schemes to Muhammad Aimal Khan, owner of M/S National Builders. The bureau stated that these schemes had been shown executed as per record, wherein grave illegalities including ghost and substandard schemes were identified during the course of investigation. It said the accused Nisar Aziz recorded fictitious measurements, ghost and unexecuted or partially executed schemes and signed bogus entries in Measurement Books on the basis of which payments were made to the contractor. The accused persons will be produced before an accountability court today for obtaining their physical remand.