"Home Ministry officials went to her residence and read it out to her," the source said of the order extending the Nobel Laureate's detention, which was due to expire on Sunday.
The order was issued despite urgent appeals from the White House, European Union, United Nations and fellow Nobel peace prize winners to the generals in charge of the former Burma.
Suu Kyi, 61, who has now been in detention for more than 11 of the last 17 years, is being held under an obscure security decree that has to be renewed every 12 months.
Quite why the junta, which ignored a sweeping election victory by her National League for Democracy in 1990, makes such a show of observing the rule of law in keeping her in isolation, without a telephone and requiring military permission to receive visitors, is a mystery.
"They just make the laws for their own convenience," Khun Saing, an exiled dissident now living in neighbouring Thailand, told Reuters this week.
Suu Kyi's latest stretch of detention started "for her own safety" on May 30, 2003, after clashes between her supporters and pro-junta demonstrators.
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