KINSHASA, Jan 17 (Reuters) - Former Guinean President Alpha Conde, ousted in a coup in September, boarded a plane on Monday to go abroad for a medical check-up, two sources said, without revealing his destination. Last month, the ruling junta said the ex-president would be allowed to travel on medical grounds but could not remain abroad for more than a month. read more A source close to Conde said he boarded a plane at 2 p.m. (1400 GMT). A top government official confirmed he had left. The September coup was condemned by Guinea"s neighbours and international partners, and led to its suspension from the African Union and the regional Economic Community of West African States (ECOWAS) 15-nation bloc. Conde, 83, who had been in power since 2010, was detained by the junta after his ouster by military officers who accused the government of endemic corruption.