Timberland shoes are seen in a shop in Rome, Italy. [Reuters]

The U.S. parent company of Timberland, Vans and Kipling will no longer buy Brazilian leather, it said on Thursday, as continuing forest fires in the Amazon raise questions about ecological stewardship in the world’s largest rainforest.

Thousands of forest fires in the Amazon have been raging for weeks, which has already led to heightened scrutiny of Brazil’s beef industry, one of the country’s main economic engines.

The holding company, VF Corp (VFC.N), said it would resume buying Brazil leather when “we have the confidence and assurance that the materials used in our products do not contribute to environmental harm in the country.”

The move was one of the first signs of a concrete economic impact from the controversy over the fires, which Brazilian President Jair Bolsonaro has insisted are under control.

Many of the fires burning were initially set by cattle ranchers or farmers in a bid to clear land. An investigative report in July by local news media showed that JBS SA (JBSS3.SA), the world’s largest meatpacker and the world’s largest leather producer, had been buying cattle from ranchers operating on land that the government has said must not be used for grazing.

JBS denied the report, although it acknowledged the difficulty of tracing some cattle’s origin.

In a statement sent to Reuters, VF Corp said, “As a result of this detailed diligence, we are no longer able to satisfactorily assure ourselves that our de minimis volume of leather purchased from Brazilian suppliers upholds this commitment.

“Therefore, VF Corporation and our brands have decided to no longer directly source leather and hides from Brazil for our international businesses until we have the confidence and assurance that the materials used in our products do not contribute to environmental harm in the country.”

The Greensboro, North Carolina-based company’s other brands include Dickies, Smartwool and The North Face.