On Sunday, a Home Ministry source said officials had visited the detained opposition leader in her Yangon home to read her a statement outlining the decision.
The visit came a year after she received a 12-month extension of her detention.
U Lwin – a spokesman for Aung San Suu Kyi’s National League for Democracy (NLD) which won a landslide election victory in 1990, only to be denied power by the army – said they had been kept in the dark about any possible extension.
Aung San Suu Kyi, 60, has spent about 10 of the last 15 years either in prison or under house arrest.
The ruling military government – which has run Myanmar, formerly known as Burma, under various guises since 1962 – shows little sign of wanting to loosen its grip on power.
Aung San Suu Kyi entered politics to work for democratisation, helped found the NLD on 27 September 1988 and was put under house arrest in 1989 by the military government.
She was offered freedom if she left the country, but she refused.
In 1990, the military called general elections, which the NLD won decisively.
Myanmar’s military government
Under normal circumstances, Aung San Suu Kyi would have assumed the office of prime minister. Instead, the results were nullified and the military refused to hand over power.
This resulted in an international outcry, and partly led to Suu Kyi winning the Sakharov Prize that year and the Nobel Peace Prize the following year.
She was released from house arrest in July 1995, although it was made clear that if she left the country to visit her husband and children in the United Kingdom, she would be denied re-entry.
As a result, she remained in Myanmar.
Her latest period in custody started on 30 May 2003 after pro-government demonstrators attacked her convoy as she travelled in the countryside north of the capital.
As part of a seven-step “road map to democracy”, a National Convention to draw up a new constitution is due to restart on 5 December, although diplomats and analysts have dismissed the military-dominated negotiations as a sham.
The NLD, allowed to field just a handful of delegates out of more than 1000, has chosen to take no part in the convention.
Despite sanctions from the United States and Europe, and a more conciliatory policy of “constructive engagement” by Myanmar‘s Southeast Asian neighbours, few analysts expect Suu Kyi’s release any time soon.