Many are deliberately electrocuted or poisoned by people who have taken forest land for farming, according to the Voice for Asian Elephants Society (VfAES).
The felling of forests for mining and other human activity also shrinks their natural habitats.
And poachers wanting tusks for ivory have been emboldened by an absence of forest patrols, which have been cut back during the coronavirus pandemic.
The VfAES accused authorities of using Covid “as a shield to avoid their responsibilities” in carrying out patrols and cracking down on corruption.
Sangita Iyer, a biologist and the organisation’s founder, said: “There is a silent catastrophe unfolding across India.
“The situation in Odisha is dire. Apathy, complacency, dereliction of duty and a significant lack of accountability by certain forest officials are some of the core issues on the ground.”
Ms Iyer accused ministers of failing to investigate the problems behind the “senseless and preventable” deaths.
She said elephant tusks have been seized from the homes of corrupt officers who know where elephants can be found and tip off poachers.
“What chance do these animals have if the very people entrusted to care for them actually end up betraying these voiceless animals?” she said.
Records show at least 82 Odisha forest officials have been accused of corruption in five years, according to the Hindustan Times.
There are 40,000 Asian elephants in the world, officially classed as endangered, 60 per cent of them in India.
But activists say a burgeoning human population, causing “reckless” land use, such as mining and agriculture expansion, and railways and roads cutting through habitats is killing the creatures.
According to a report by Traffic, a wildlife trade monitoring charity, during the pandemic the poaching of large mammals in India has increased by 44 per cent, and that of other small mammals by 25 per cent.
It’s feared the official elephant death tally is an underestimate because villagers who normally find carcasses have been out less.
In 2012, the Odisha government announced that every unnatural death would be investigated, but Ms Iyer claimed ministers have not questioned or reprimanded any officials for failing to prevent deaths.
And she called on the government to launch a thorough investigation into the deaths.
In the longer term, underpasses and overpasses should be built for railway tracks and roads to prevent elephant deaths, she said, and drivers flouting the traffic laws should be suspended.
“The consequences of the disappearance of Asian elephants would be colossal to the forest ecosystems, not only in India, but around the world, as elephants play a vital role in climate mitigation. Their decimation simply cannot be underestimated,” she added.
Maria Mossman, founder of Action for Elephants UK, said: “This kind of mistreatment of elephants in a state that houses India’s fifth-largest population will tarnish Odisha’s reputation around the world.”
Odisha government has not responded to requests from The Independent for comment by the time of publication.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies