Myanmar's Supreme Court on Monday refused to allow two more witnesses to appear in defence of opposition leader Aung San Suu Kyi, who is facing charges of breaking the terms of her detention and a possible five-year jail sentence, her lawyer said.

Court judges rejected a request by Suu Kyi's defence team to allow Tin Oo and Win Tin, two senior opposition politicians, to appear as witnesses in the controversial case, Nyan Win, one of Suu Kyi's attorneys, said.

Tin Oo, the deputy leader of the National League for Democracy (NLD) party, which Sun Kyi heads, is currently under house arrest, which disqualified him as a witness, court officials said. The court apparently disqualified Win Tin, a senior NLD member and former journalist, for his differing views with Myanmar authorities.

Suu Kyi's case, being held at a special court set up in Yangon's Insein Prison, is to resume Friday when defence witness Khin Moe Moe, an attorney, is scheduled to testify, Nyan Win added.

Suu Kyi's trial began May 11. While the prosecution was allowed to present 14 witnesses in the first week, the defence was initially allowed only one. Later a second witness was permitted.

Suu Kyi, who has spent 13 of the past 19 years in detention, stands accused of breaking the terms of her latest house detention by permitting US citizen John William Yettaw, 53, to swim to her home-cum-prison on Yangon's Inya Lake May 3 and spend two nights there before swimming away.

Critics have accused the military junta of using the case as a pretext to keep the 1991 Nobel Peace Prize laureate in jail during a politically sensitive period leading up to a general election planned for next year.

Suu Kyi's NLD won the 1990 general election by a landslide but has been blocked from power by Myanmar's junta for the past 19 years.

The new trial of Suu Kyi, whose most recent six-year house detention sentence expired May 27, has sparked a chorus of protests from world leaders and even statements of concern from its regional allies in the Association of South-East Asian Nations.

UN special envoy to Myanmar Ibrahim Gambari was in the country over the weekend, reportedly to pave the way for an official visit by his boss, UN Secretary General Ban Ki-moon.

The outcome of Gambari's visit has yet to be announced.