In a letter to Modi, who is also the chairman of the National Board for Wildlife, animal rights group Heritage Animal Task Force said elephant contractors and festival organizers widely use such instruments to keep the elephants under control.
It is a violation of laws enacted for ensuring prevention of cruelty to jumbos, it said.
The outfit alleged that a 73-year-old jumbo, which ran amok inside the Konni elephant camp in Pathanmthitta district recently, was tied using banned instruments like capture belt after tranquilising the animal twice.
The outfit also alleged that officials concerned had not taken any steps to prevent such practices though the matter had been brought to their notice.
Heritage Animal Task Force urged the authorities to initiate stringent actions against all these types of cruelty to elephants with immediate effect.