The UN today said it would suspend aid shipments to Burma after discovering all supplies sent in so far have been seized by the ruling military junta.
An official said the World Food Programme had no choice but to stop sending supplies until the matter was resolved.
WFP spokesman Paul Risley said that all "the food aid and equipment that we managed to get in has been confiscated".
The shipment included 38 tons of high-energy biscuits.
He said it was not clear why the material was seized.
Mr Risley said: "It is being held by the government. We are waiting resolution of this matter."
Meanwhile, more than a million people made homeless in last Saturday's cyclone waited for food, shelter and medicine. Many crammed into Buddhist monasteries or just camped out in the open.
Entire villages were submerged in the Irrawaddy delta, with bodies floating in salty water and children ripped from their parents' arms. At least 62,000 people are dead or missing, state media reported, and aid groups warned that thousands of children may have been orphaned and the area is on the verge of a medical disaster.
The WFP had sent some aid on a scheduled Thai Airways cargo flight yesterday which went through without problems.
But a bureaucratic mix-up led to the seizure when two flights landed today, Mr Risley said.
"For the time being, we have no choice but to end further efforts to bring critical needed food aid into (Burma) at this time," Mr Risley said.
The secretive regime has also refused to grant visas to foreign aid workers who could assess the extent of the disaster and manage the logistics.
"The frustration caused by what appears to be a paperwork delay is unprecedented in modern humanitarian relief efforts," said Mr Risley. "It's astonishing."
He said the WFP submitted 10 visa applications around the world, including six in Bangkok, but none has been approved.
"We strongly urge the government to process these visa applications as quickly as possible, including work over the weekend," he said.
The junta said it was grateful to the international community for its assistance - which has included 11 chartered planes loaded with aid supplies - but the best way to help was just to send in material rather than personnel.
One relief flight was sent back after landing in Rangoon yesterday because it carried a search-and-rescue team and media who did not have permission to enter the country.