Yangon, Feb 26 (DPA) Myanmar's Supreme Court Friday turned down an appeal by opposition leader Aung San Suu Kyi against her sentence of 18 months of house detention, which would keep her confined during a general election planned this year, her defence lawyers said.

A special prison court handed down the sentence Aug 11 to Suu Kyi, 64, for breaking the conditions of her previous detention term.

It convicted the winner of the 1991 Nobel Peace Prize, who has spent 14 of the past 20 years under house arrest, of allowing US national John Yettaw to stay at her lakeside home and detention centre in Yangon after he swam there uninvited on the night of May 3.

Suu Kyi had earlier appealed the case to the Myanmar Appeal Court, which upheld the sentence, and then took it to the Supreme Court, which also upheld the original sentence.

'The court rejected Aung San Suu Kyi's appeal,' said Nyan Win, one of her lawyers. 'It's not surprising.'

Her latest sentence was widely condemned by the international community as an excuse to keep Suu Kyi, leader of the National League for Democracy opposition party, out of the political scene as the ruling military junta stages a general election some time this year.

Her lawyers argued that the charge of breaking her terms of incarceration harked back to the 1974 constitution, which had been superseded by a new constitution adopted in 2008.

Myanmar has been under military rule since 1962. Its judiciary has a long record of bowing to military demands on controversial cases.