So far, he has met the head of military intelligence, General Khin Nyunt, and the Foreign Minister, Win Aung. But it is unclear whether Mr Pinheiro will also meet the pro-democracy leader, Aung San Suu Kyi, who has been under house arrest since September last year. Analysts believe the general's decision to allow Mr Pinheiro access to Burma is another sign that significant changes are taking place in Rangoon. The BBC's Southeast Asia analyst, Larry Jagan says the UN official's visit to Burma is still shrouded in secrecy. It is unclear whether Mr Pinheiro will meet Aung San Suu Kyi Diplomats in Rangoon believe the full schedule for the visit will be worked out with the generals in Rangoon.
Analysts say the visit can only be a confidence-building mission.
Unlike his predecessors, Mr Pinheiro has avoided holding extensive discussions with human rights activists or Burmese opposition figures. Instead he has spent nearly a week in the region talking to some of Burma's neighbours - Japan, Malaysia and Thailand in particular. UN sources say this is a fresh approach to the job and one that they hope may produce concrete results on the human rights front. Many of these Asian governments are also expected to support a highly critical resolution on Burma, which will be discussed at the human rights commission in a fortnight's time. Diplomats in Rangoon believe that the military government has permitted Mr Pinheiro to visit in the hope of deflecting some of the more critical aspects of the proposed resolution.