Kuwait's supreme court on Sunday upheld a two-year jail sentence for opposition activist Ayyad al-Harbi over tweets deemed offensive to the Gulf state's ruler.
Harbi, a journalist in his 20s at the Sabr news website, has been behind bars since May after an appeals court confirmed the original prison sentence.
Online activists strongly criticised Sunday's ruling, which is final.
They said Harbi had only re-posted on Twitter verses in which Iraqi poet Ahmad Matar blasted Arab rulers.
Criticising the emir is illegal in Kuwait and is considered an offence against state security. Those convicted can be jailed for up to five years.
Harbi is among several online activists currently in prison.
In February, former lawmaker Mussallam al-Barrak was sentenced to two years for insulting the emir at an opposition gathering in 2012.
The supreme court is due to hear his appeal on April 13.
The public prosecutor, meanwhile, on Sunday freed on bail two Shiite activists after they had been held for five days for questioning over tweets about Yemen, their lawyer Jalil al-Tabbakh said.
Khaled al-Shatti, a lawyer and former MP, and Salah al-Fadhli, a writer and academic, were arrested on Wednesday over comments they wrote on Twitter deemed offensive to the emir and critical of neighbouring Saudi Arabia.
The tweets criticised the Saudi-led air strikes against Shiite Huthi rebels in Yemen and objected to Kuwait taking part in the operation.
Tabbakh said in a statement the public prosecutor agreed to free the two on bail of 3,000 dinars ($10,000) each pending further investigation.