A member of the body that oversees the sustainability of the London Olympics has resigned in protest at a sponsorship deal with Dow Chemical because of the American company's ties to the 1984 Bhopal gas disaster that killed thousands in Madhya Pradesh.
The Games' organisers chose Dow to make the hundreds of plastic panels that will decorate the outside of the main stadium in a contract that has angered many Indians, including current and former Olympic athletes.
Activists say 25,000 people died in the years that followed the gas leak at a pesticides factory in Bhopal. Dow bought the plant's owner in 1999 and campaigners have demanded that it boosts a 1989 compensation package for those affected by the disaster.
Meredith Alexander, who sat on the Commission for a Sustainable London 2012, said she had decided to quit the independent body because she "didn't want to be party to a defence of Dow".
"People should be free to enjoy London 2012
"It is appalling that 27 years on, the site has still not been cleaned up and thousands upon thousands of people are still suffering."
No one at the Olympics organising body could immediately be reached for comment. Dow has denied any responsibility for the accident and says the former owner, Union Carbide, had settled its liabilities with the Indian government.
Amnesty said the Games' organisers should admit they were wrong in awarding the contract to Dow, who are also a worldwide partner of the International Olympic Committee (IOC).
"This high profile resignation means the London 2012 organisers can no longer ignore human rights concerns about Dow, a company that has refused to meet its responsibilities in relation to the victims of Bhopal," Amnesty's Seema Joshi said in a statement.