Police took 64-year-old Ohn Kyaing from his home on Wednesday evening, said Mr Nyan Win, the spokesman for Suu Kyi's National League for Democracy.

'The reason why he was detained was not known,' Mr Nyan Win said.

Ohn Kyaing was released from prison in 2005 after serving 15 years of a 17-year prison sentence for 'writing and distributing seditious pamphlets' and threatening state security.

Ohn Kyaing joined the NLD after a long career in journalism and won a parliamentary seat in 1990 - elections that were overwhelmingly won by Suu Kyi's party but which the military junta refused to recognise.

Until then, he had worked at several newspapers and written articles under the pen name 'Aung Wint.'

Ohn Kyaing is a close friend and former colleague of Mr Win Tin, another former journalist turned opposition politician, who was the longest-serving political prisoner in Myanmar until his release Sept 23. Mr Win Tin served 19 years behind bars.

Asked to comment on the detention of Ohn Kyaing, mr Win Tin said, it 'is not unusual and something we have to expect. He is a close colleague, a good friend and a highly qualified man.'

The Home Ministry, which is in charge of police, could not be reached for comment on Thursday. Authorities seldom comment on arrests of this nature.

Myanmar has been under military rule for 46 years and is one of the world's poorest and most authoritarian nations.

Suu Kyi, a Nobel Peace Prize laureate, has been detained for 13 of the last 19 years. -- AP