TURKEY’S opposition People’s Democratic Party (HDP) has demanded the immediate release of “political hostage” Leyla Guven, who won a seat in parliament in the June 24 elections.

The party accused the authorities of holding Ms Guven “illegally” after a court ruled on Friday that she should be released. 

She was arrested on January 22 and accused of terrorist activities following social media posts opposing Operation Olive Branch, Turkey’s illegal invasion and occupation of Afrin in northern Syria.

Her release was ordered by the Ninth Heavy Penal Court in Diyarbakir, which cited a lack of adequate evidence against Ms Guven. However, the prosecutor, who is seeking a 31-year jail term for allegedly “establishing and managing an armed terrorist organisation” and “making propaganda for terrorists,” objected to the ruling at a higher court.

Ms Guven, who was elected in the south-eastern province of Hakkari to the Turkish parliament, was arrested on the orders of the higher court after it accepted the objection.

HDP deputy co-chair Ayse Acar Basaran branded the decision “outrageous” and warned that the MP has “already suffered a brutal and illegitimate detention based on unfounded and abstract allegations.”

“Leyla Guven’s freedom was arbitrarily taken away by the prosecutor’s office, despite [her detention] being illegal,” she charged.

Ms Basaran complained that the decision was taken too swiftly by the appeals court, arguing that it could not have possibly reviewed the case as it was “busy in another session.”

It reportedly took just 10 minutes for the 10th Heavy Penal Court to read and review the five-folder case file.

Ms Basaran accused the court of making the decision to detain Ms Guven based on “instructions” and questioned the legality of a court which “does not have authority on the case” overturning the decision of another court.

“Leyla Guven continues to be held hostage unlawfully and arbitrarily” she said, demanding that she be “released immediately without further obstacles.”

Ms Guven was arrested in December 2009 as part of an operation against the Kurdistan Communities Union (KCK).

She was held in prison for five years before being released in 2014.

The HDP scored 11.7 percent of the vote in last month’s  parliamentary elections, winning 67 MPs, while presidential candidate Selahattin Demirtas finished third on 8.4 per cent, despite having to campaign from a prison cell.

Former HDP co-leader Figen Yukeskdag faces trial in Ankara on Friday. If convicted, she faces life imprisonment.