British diplomats in Khartoum have demanded that the vehicles, computers, office equipment, medical stores and cash be returned so that it can be redistributed.
But Sudanese officials have scoffed at this, saying that neither the British government nor the aid agencies have “the right to control these assets”.
Up to £500,000 worth of British-funded goods were seized from groups primarily working in Darfur, according to the Department for International Development.
Khartoum took the assets when it expelled 13 aid agencies in March in apparent retaliation for President Omar al Bashir being indicted for war crimes by the International Criminal Court.
“We have made it clear to the Sudanese government that all seized goods must be returned and are now discussing how best to reassign these assets to ongoing humanitarian efforts,” a spokesman for DfID said in a statement.
In total, Oxfam and Medecins Sans Frontieres’ French and Dutch operations have reported that they lost roughly £3.25 million of equipment.
They had also been forced to pay another £5.6 million to Sudanese staff as lay-off payments because of the shutdown.
Sudan has demanded the right to redistribute the materials to its choice of aid agencies working in Darfur.
But there are grave fears that they might end up in the hands of organisations without the necessary experience, meaning millions of pounds of British aid will go to waste.