Cuttack: An environment activist has alleged that the temporary helipad where Prime Minister Narendra Modi's chopper landed in Cuttack on Saturday was built in violation of a National Green Tribunal order.

The helicopter had landed on the Mahanadi's floodplain near the Gadgadia temple, close to the Killa Maidan where Modi addressed a public meeting.

Activist Biswajit Mohanty claims the landing of the chopper and the movement of Modi's convoy were in "clear violation of the restrictions" the tribunal had imposed last October on constructions and activities on the floodplains. He said he would take the matter to the tribunal.

Cuttack collector Sushanta Mohapatra could not be reached. District emergency officer Prabodh Rout said: "Permission was given (by the administration) for use of the lower Bali Yatra ground as a helipad as it involved no permanent construction."

The Bali Yatra is an annual festival. "The tribunal's order only allows the Bali Yatra to be held on the floodplain for seven days under several conditions," Mohanty said.

He said the floodplain had endured several trial sorties and vehicular movement over the past three days.

Mohanty accepted that the helipad was built at the site "on grounds of security and proximity to the venue of the Prime Minister's rally", but felt the administration should have sought the tribunal's permission.

The October 16 order of the tribunal's east zone bench in Calcutta had barred "encroachments", dumping of wastes or "illegal constructions" on the floodplain.