Sherwan Sherwani is the former editor of the monthly Bashur, known for its investigations into corruption.

He was arrested in 2020 and jailed the following year for "espionage" and "incitement to protest and destabilise the region".

He had been due for release in September following a presidential decree reducing his sentence, according to the Committee for the Protection of Journalists.

But on Thursday, the CPJ said, Sherwani was given a four-year prison term for "falsification" in connection with a petition prepared in jail.

His lawyer Ramazan Artisi said Sherwani was accused of falsifying the signature of a fellow prisoner, despite that inmate authorising him to do so.

"The verdict is unfair," Artisi said, adding that he would appeal.

On Sunday, around 300 people demonstrated in the region's second city Sulaimaniyah against the new sentence imposed on Sherwani.

"His second conviction shows there is no independent justice in Kurdistan, and there is clear political pressure," said one activist, Samale Rahim.

Activists say corruption and arbitrary arrests are widespread in Kurdistan, which presents itself as an oasis of stability.

NGO Community Peacemaker Teams said Saturday Sherwani did not get a fair trial, but a Kurdistan government body, after reviewing the proceedings, said Sunday that powers of attorney between prisoners were illegal.