Nazar Ahari was arrested last December on her way to the funeral of an opposition spiritual leader [AFP]

An Iranian court has sentenced a prominent human rights activist to six years in prison on various anti-government charges, a semi-official Iranian news agency has reported.

ILNA news agency said on Saturday that Shiva Nazar Ahari was convicted of gathering and plotting to commit crimes against the Iranian state, propaganda against the establishment and waging war against God, a crime punishable by death under the Islamic Republic's Sharia law.

Nazar Ahari, the 26-year-old founder of the Committee of Human Rights Reporters in Tehran, was arrested in December on her way to the funeral of Grand Ayatollah Hossein Ali Montazeri, the spiritual adviser of the Green movement which opposed the re-election of Mahmoud Ahmadinejad, the Iranian president, last June.

In addition to the jail term, she has to pay a $400 fine or face 74 lashes, Mohammad Sharif, her lawyer said.

Sharif vowed to appeal the verdict, saying there was "no legal basis for this charge".

She was also arrested shortly after the disputed June 2009 presidential vote and released only after spending three months in Tehran's Evin prison, where dozens of activists and journalists are still being held.

Human rights groups have dismissed the claims against her as “trumped-up charges'' stemming from her participation in the 2009 protest rallies.

The opposition says the election was rigged, but authorities denied that and blamed foreign powers for stirring agitation.