The Burma military junta's arrest of a popular comedian campaigning for victims of Cyclone Nargis is part of continuing serious human rights violations in the country, a United Nations investigator said.
Tomas Ojea Quintana also told a news briefing there were political prisoners in the country, despite the regime's insistence it imprisons law breakers.
"The latest information coming to me in the last few days builds up a picture of a serious situation of violations of human rights in Myanmar [Burma]," said Mr Ojea Quintana, an Argentine lawyer who has just taken up his UN post.
News reports from Rangoon said the comedian, known by his stage name of Zarganar, was detained last Wednesday (local time) by police who seized his computer and banned film and recordings of the devastation caused by the cyclone.
Mr Ojea Quintana, whose own parents were political prisoners under a military regime in Argentina, said he had asked the Burma authorities for clarification and for information on Zarganar's whereabouts, but had received no reply.
As special investigator for Burma, he reports to the UN's 47-nation Human Rights Council at which he called last week for release of all political prisoners, starting with Nobel laureate and Opposition leader Aung San Suu Kyi.
Burma's ambassador in Geneva denied his government arrested people for political reasons. He also rejected another assertion by the investigator that soldiers had shot prisoners on the night of the cyclone on May 2.
Mr Ojea Quintana said he understood the prisoners, in a jail at Insein in the Irrawaddy delta where Nargis struck with full force, were trying to flee the partially destroyed facility to save their lives.
In his report, he asked the Burmese authorities to investigate assertions by a Thailand-based activist group that 36 prisoners had died when police and troops moved in to quell what they said was a riot.
The investigator said he hoped to be able to establish an open dialogue with the Government on Burma and to be given permission to visit the country to check information coming into his office. But so far no clearance had come from Rangoon.