Bahrain's top court on Monday reduced the jail sentence of Shiite opposition leader Sheikh Ali Salman, who has been in prison since 2014, a judicial source said.
The Sunni-ruled kingdom's court of cassation reduced Salman's sentence from nine to four years, the source said on condition of anonymity.
No further details were immediately available.
Salman, who headed the now-banned Al-Wefaq opposition movement, had been arrested on charges of inciting hatred and insulting the state in December 2014.
He was found guilty in July 2015 and sentenced to four years in jail.
An appeals court later more than doubled his jail term to nine years, after reversing an earlier acquittal on charges of calling for regime change by force.
The court of cassation in October had ordered a retrial of the 51-year-old Salman.
Rights groups downplayed the significance of Monday's verdict in the retrial, which comes amid an ongoing crackdown on political dissent in Shiite-majority Bahrain.
"Peacefully criticising the government or demanding reform is not a crime and should not be a punishable offence under any circumstances," said Lynn Maalouf, research director at Amnesty International's Beirut office.
"Instead of placing (Ali Salman) behind bars for four years, the Bahraini authorities should order his immediate and unconditional release and end their relentless persecution of peaceful critics and opposition leaders once and for all."
Salman is considered a moderate who has pushed for a constitutional monarchy in Bahrain compared to more hardline groups who have demanded the toppling of the Sunni Al-Khalifa dynasty in a string of protests that go back to 2011.
Bahrain has cracked down over the past six years on dissent by members of the largely, although not exclusively, Shiite opposition, whom it accuses of being manipulated by Iran.
Shiite Iran has consistently denied any involvement.
The kingdom last year ordered the dissolution of Al-Wefaq, the kingdom's main Shiite opposition group, for "harbouring terrorism".
Al-Wefaq was the largest bloc in Bahrain's elected lower house of parliament.
Its lawmakers resigned en masse in protest against the state crackdown on the 2011 protests.
In 1995, Salman was among a string of oppositionists exiled from Bahrain, moving to the United Arab Emirates and then Britain.
In 2001, he returned to Bahrain under a general amnesty and set up Al-Wefaq National Islamic Society with other Shiite opposition figures.
In 2006 he was elected secretary general of the group.

Source: AFP