LIMA (Reuters) - Dozens of environmental group sharply criticized organizers of the Tokyo 2020 Olympics on Monday for alleged exploitation of tropical rain forests, claiming this was also potentially fuelling human rights violations.

File Photo: Tokyo 2020 Olympic (L) and Paralympic Games emblems are displayed at Tokyo Metropolitan Government Building in Tokyo, in this July 24, 2015 file photo. REUTERS/Issei Kato/Files

In an open letter to the International Olympic Committee (IOC), which is meeting in the Peruvian capital, 47 NGOs, including Greenpeace, said there was mounting evidence the Tokyo Games were using timber through companies associated with illegal logging and human and labor rights violations.

They added that organizers had not been transparent about the sourcing of the wood used in construction projects for the Games.

“Mounting evidence that Tokyo 2020 is exploiting tropical forests and potentially fuelling human rights violations is jeopardizing the Olympic commitment to sustainability and respect for human dignity,” they said.

“We urge the International Olympic Committee (IOC) and Tokyo 2020 authorities to immediately disclose the timber supply chain associated with the Tokyo 2020 Olympics, including the origin and volume of all tropical wood used, and to halt further use of wood from tropical forests and other high risk sources.”

Tokyo Games organizers could not be immediately reached for a comment.

Tokyo’s preparations for the Olympics have been anything but smooth with projected costs ballooning to more than $26 billion, though organizers reduced that to $16.8 billion late last year.

“Unfortunately, the Tokyo 2020 authorities have been secretive about the timber used for the Tokyo 2020 Olympics and have failed to take sufficient action to mitigate the risk of using illegal and unsustainable tropical timber,” the letter said.

The group of signatories, which includes the Center for International Environmental Law in the United States and Germany’s Gesellschaft fuer Oekologische Forschung (Society for Environmental Research), said sourcing from controversial suppliers, with a record of tropical forest destruction and violating logging practices, was a contradiction of Olympic values and commitments.

This is not the first time environmental groups have raised concerns over the use of timber for the Tokyo Games, with the IOC pushing to reduce the size and cost of future Games with potential hosts having been scared off in recent years.

The relocation of Tokyo’s Tsukiji fish market, a popular tourist destination, to build an access road that will cut down travel time for athletes has also been an environmental problem.

It has been delayed because of concerns about the clean-up of toxic pollution at its proposed new home, including unsafe levels of cancer-causing benzene.