The US Agency for International Development suspended food aid to Ethiopia after an investigation showed supplies from international donors was being diverted or sold.

The decision by USAID could impact more than 20 million people already affected by violence and climate change in the Horn of Africa nation that’s emerging from a two-year civil war.

“After a country-wide review, USAID determined, in coordination with the Government of Ethiopia, that a widespread and coordinated campaign is diverting food assistance,” a spokesperson said in an emailed statement on Thursday. “As a result, we made the difficult but necessary decision that we cannot move forward with distribution of food assistance until reforms are in place.”

A probe over the past two months found that donor-funded food had been re-purposed and sold at private markets and in some cases exported abroad, documents seen by Bloomberg show.

The scheme was allegedly orchestrated by federal and regional government entities in Ethiopia, as well as private grain and flour traders. It also benefited military units nationwide, according to the documents.

Spokespeople from the Ethiopian government and the National Disaster Risk Management Commission of Ethiopia didn’t response to emails and calls seeking comment.

Read more: The Two-Year Conflict That’s Torn Ethiopia Apart: QuickTake

Last month, the UN’s World Food Programme decided to pause food distributions in the northern Tigray region, the epicenter of the war, after finding evidence of significant aid sales in local markets. A spokesperson for the WFP didn’t respond to emails seeking comment.

Police in Ethiopia last month arrested Mitiku Kassa, the former head of the national disaster commission, for alleged corruption.

The USAID allegations could affect debt relief negotiations the government is holding with creditors, including the US, under the Group of 20 Common Framework, and come as the nation faces a shortage of foreign exchange.