A Bahraini court has rejected a request for early release from the jailed human rights activist, Nabeel Rajab.
A judicial source told the AFP news agency Mr Rajab's lawyers had argued he was eligible because he had served three-quarters of a two-year sentence.
The prominent activist was convicted in August 2012 of taking part in illegal gatherings and disturbing public order.
Last week, Amnesty International said Mr Rajab had been detained in "inhumane and humiliating conditions".
"His detention for taking part in a peaceful protest shows the lengths to which Bahrain's authorities will go to stamp out dissent," said the group's Middle East and North Africa deputy director, Hassiba Hadj Sahraoui.
"His case also shows how, despite repeated promises of reform, Bahrain continues to flout its international human rights obligations."
Failing to release him "would make it crystal clear that his imprisonment is not about justice or the law but about silencing him", she added.
Mr Rajab is the president of the Bahrain Centre for Human Rights (BCHR) and deputy secretary general of the International Federation for Human Rights (FIDH).
Before his imprisonment in July 2012, Mr Rajab was repeatedly detained in connection with the pro-democracy protests that erupted in the Gulf kingdom the previous year.
Amnesty said that he was punched in the face several times by riot police as he led a demonstration in February 2012, and in May 2012 was charged with "insulting a national institution" in comments about the interior ministry he posted on Twitter.
In June 2012, Mr Rajab was sentenced to three months in jail over different tweets he wrote about the prime minister. The conviction was eventually overturned on appeal, but only after he had begun his two-year sentence for taking part in unauthorised protests.
At his trial, Mr Rajab told the court that he had been held in dire conditions and subjected to ill-treatment, including being placed in solitary confinement with a dead animal and kept almost naked, with only a small piece of cloth covering his genitals.
In a letter published after the BCHR was awarded the Rafto Prizefor human rights defenders in September 2013, Mr Rajab wrote: "Brutal violations are still continuing today against peaceful Bahrainis while the whole world continues to stay silent, especially Bahrain's Western allies.
"Our nation is a victim of being in an oil-rich region and a victim of hypocrisies and double standards. Unfortunately, dictators of the Gulf region succeeded in silencing governments of the free world in return for short-sighted economic and financial gains."
The BCHR's founder, Abdulhadi al-Khawaja, is serving a life sentence for allegedly plotting to overthrow the government. He was convicted on evidence that was widely accepted as having been secured under torture.