Rajab was granted bail in a pending trial relating to the spread of false information, with the case to resume on January 23. He is being kept in jail to be questioned in another cybercrime case on a similar charge.
A court in Bahrain has approved bail for a leading activist, Nabeel Rajab, on Wednesday but he remanded in prison due to other charges filed by a public prosecutor.
Rajab was granted bail in a pending trial relating to the spread of false information, with the case to resume on January 23.
But the activist was being questioned in another cybercrime case on a similar charge of "spreading false news about the situation in the kingdom."
Rajab, founder of the Bahrain Centre for Human Rights, said on his Twitter account that the prosecutor decided to keep him in prison over other charges despite the court's order to release him.
Rajab was arrested in June after he allegedly posted tweets about the Gulf Arab kingdom's prison system and its involvement in the war in Yemen.
Rajab played a leading role 2011 demonstrations demanding reforms in the Gulf Arab kingdom.
Bahrain quelled the 2011 protests but has since struggled to resolve a political deadlock between the government and opposition.
Rajab has been repeatedly detained for organising protests and publishing tweets deemed insulting to Bahrain's authorities. He previously served two years in jail on charges of taking part in unauthorised protests in the kingdom.