The National Green Tribunal on Friday warned the Directorate General of Civil Aviation for “repeated defiance” on issuing a circular to airlines operating at Delhi’s Indira Gandhi International airport to ensure they do not dispose human waste mid-air, PTI reported.

A bench of tribunal chairperson Justice AK Goel and Justice Jawad Rahim said that the salary of the director general of civil aviation would be withheld if the order was not complied with by August 31.

The bench said that the directorate had not given a valid explanation nor did it comply with the tribunal’s order. “Since there is a repeated defiance by the DGCA with absolutely no acceptable explanation, we have no option but to direct the DGCA to comply with the directions already issued on or before August 31,” the bench said.

The tribunal also warned the aviation regulator that if there was “continued defiance”, it may have to consider prosecution of the director general on the next date of hearing, September 17. The bench said the director general may be required to be present in person if the order is not complied with.

During the hearing, the DGCA told the bench that it has not complied with the order as a review petition against the tribunal’s order was pending adjudication. The DGCA in May sought a stay and review of tribunal’s orders dated December 20, 2016 and January 10, claiming it was impossible to empty toilet tanks during flights.

The tribunal’s order was based on a petition filed by Lieutenant General (retired) Satwant Singh Dahiya alleging that faeces were splattered from an aircraft on his South Delhi house before Diwali in 2016.