An estimated 2.4m cyclone survivors remain homeless and hungry
Burma's most famous comedian has been detained after leading a private effort to deliver aid to cyclone victims.
The family of the man, known as Zarganar, said police searched his house in Rangoon and arrested him.
The junta has been heavily criticised for obstructing foreign aid efforts and many Burmese volunteers have organised their own deliveries to survivors.
An estimated 2.4m people remain homeless and hungry following the cyclone, which struck on 2 May.
Two hundred aid experts from South-East Asian countries are now being deployed in the Irrawaddy Delta region to assess the needs of survivors.
The task force will produce a report on the humanitarian situation in the region for a meeting of the Association of South-East Asian Nations in Rangoon on 24 June.
But despite recent changes to government policy, allowing aid workers more access to affected regions, the international community remains critical of the government.
US Navy ships laden with relief supplies steamed away from Burma's coast on Thursday after waiting more than three weeks for a green light from the junta.
"The [junta] has done nothing to convince us they intend to reverse their deliberate decision to deny much needed aid to the people of Burma," Lt Denver Applehans said in an e-mail from the flotilla to AP news agency.
Meanwhile, a human rights group accused the junta of forcing cyclone survivors to do menial labour in exchange for food, and of stepping up a campaign to evict the homeless from aid shelters.
Amnesty International also cited 40 accounts of Burmese soldiers or officials having confiscated, diverted or misused aid for survivors, despite the junta's pledge to crack down on the problem weeks ago.
The government says Cyclone Nargis killed 78,000 people and left another 56,000 missing.