Jean Marie Dore, the spokesman for the main alliance of opposition parties in Guinea, the Republican Front for Democratic Change (FRAD), was arrested by police on Thursday, apparently in connection with his criticism of President Lansana Conte in a radio interview earlier in the day, opposition sources said.
Police gave no reason for arresting Dore, the leader of the Union of the People of Guinea (UPG) opposition party and an outspoken critic of the president.
However, the sources said they believed Dore had been detained in connection with his accusation that Conte had planted an unknown minor politician as a rival candidate in next month's presidential election in order to give the vote - which has been boycotted by FRAD - an appearance of democracy.
Dore said in an interview broadcast by Radio France Internationale that Mamadou Bhoye Barry, the lone challenger to Conte in the poll was "a man planted by President Conte himself to show a semblance of democracy in the election."
Barry is the lone parliamentary deputy of a small party that supports Conte's ruling Party of Unity and Progress. He is virtually unknown in political circles. The independent internet-based news service Guineenews described him as a vet who was a close friend of the president and looked after the animals on his farms.
Dore also said in the radio interview that a medical certificate certifying Conte as being fit to contest the election was a farce. The 69-year-old head of state has been in poor health for several years. He is rarely seen in public and diplomats say he often has difficulty walking.
The former army colonel has ruled this former French colony of eight million people with an iron hand since he came to power in a coup 19 years ago and is now seeking a further seven-year term.
FRAD and other opposition parties decided to boycott the 21 December presidential election earlier this month after the government refused to appoint a genuinely independent electoral commission and give the opposition free access to state radio and television.