Food aid to Ethiopia has been suspended after the discovery that humanitarian supplies meant for people in need were being stolen. The UN’s World Food Programme (WFP) said on Friday that it is halting food assistance while it rolled out “enhanced safeguards and controls that will ensure humanitarian food assistance reaches targeted, vulnerable people”. It comes a day after the US Agency for International Development (USAid) said it was doing the same, after a “countrywide review” uncovered “a widespread and coordinated campaign” that was diverting food assistance from Ethiopian people. “We made the difficult but necessary decision that we cannot move forward with distribution of food assistance until reforms are in place,” said a USAid spokesperson. More than 20 million people across Ethiopia rely on humanitarian help as civil conflict and the worst drought in four decades grips the country. The US is the largest single donor to the country, supplying aid worth $1.8bn (£1.4bn) in the past fiscal year. The USAid and the WFP had already suspended food supplies to the northern Tigray region while they investigated reports of stolen aid there. Tigray was the centre of a civil war that ended in November and nearly all of its 6 million people rely on aid. The humanitarian agencies have not apportioned blame for thefts. However, an internal memo by a group of foreign donors says that Ethiopian government officials are involved. “Extensive monitoring indicates this diversion of donor-funded food assistance is a coordinated and criminal scheme, which has prevented life-saving food assistance from reaching the most vulnerable,” the document says. “The scheme appears to be orchestrated by federal and regional government of Ethiopia entities, with military units across the country benefiting from humanitarian assistance.” The document says USAid investigators visited “63 flour mills in seven of Ethiopia’s nine regions” since March where they “witnessed significant diversion” of supplies donated by the US, France, Japan and Ukraine. Another document posted on USAid’s website in May, and later taken down, detailed instances of US-supplied grain being sold in markets throughout Tigray in March and April. This included enough wheat to feed 134,000 people for a month on sale “in a local grain market and being processed into flour at mills owned by local wholesalers” in the city of Shire, which hosts large numbers of people displaced by the war. A US official, who spoke on condition of anonymity, said that Ethiopia’s federal government was using some of the stolen aid to feed Tigrayan fighters demobilised as part of the ceasefire. Meanwhile, two humanitarian workers, who also requested anonymity, said rebel Tigray authorities had regularly taken a proportion of beneficiaries’ aid rations at flour mills during the war as a “tax”. Ethiopia has vowed to hold an investigation “so the perpetrators of such diversion are held to account”. The WFP has said its Ethiopia country director, Claude Jibidar, is on leave, amid speculation that he had resigned. In a text message to the Guardian, Jibidar would not confirm if he was returning to his post. Ethiopia experienced devastating famines and conflicts in the 1970s and 1980s. Aid agencies have long struggled to keep their food donations out of combatants’ hands. During the recent conflict, the government faced UN accusations that it restricted the flow of aid to Tigray and used “starvation as a method of warfare”, while the government accused humanitarian agencies of running arms to the Tigray rebels.