The High Court of Australia has upheld charges against South Australian woman Zainab Abdirahman-Khalif, who was convicted of joining Islamic State.

Abdirahman-Khalif denied being a member of the terrorist group after she was arrested trying to board a plane on a one way ticket to Turkey, where she said she hoped to do aid work.

She was jailed after an Adelaide jury found her guilty, but was freed on appeal.

Today the High Court threw out the appeal, after a challenge by prosecutors.

It is unclear if she will have to return to prison.

From the first arrest to the upheld charges

Abdirahman-Khalif was detained at Adelaide Airport in July 2016 trying to board a plane to Turkey with hand luggage and $180. At the time, she was released without charge.

In May 2017, she was again arrested and charged by Australian Federal Police with knowingly being a member of a terrorist organisation.

In September 2018, following a three-week trial, Abdirahman-Khalif was found guilty of being a member of the Islamic State.

It took the jury of five women and seven men about three hours to reach an unanimous verdict.

The court heard 378 audio files associated with IS were found on her phone, along with 125 videos from an IS media organisation, 62 of which contained extremist material including vision of buildings being blown up, captives being executed and dead bodies on the ground.

Abdirahman-Khalif was also in communication with three young African women who carried out a bombing in Mombasa, Kenya, in September 2016, for which IS later claimed responsibility.

The court heard she had been repeating oaths and singing songs connected to Islamic State in her bedroom.

However, late last year Abdirahman-Khalif was freed after an appeal found the prosecution had failed to present evidence of how a terrorist organisation admitted members.

One of the key issues then was whether the steps she took to go to Turkey were sufficient to link her to membership of IS.

Today, the High Court said it was up to the jury to decide whether Abdirahman-Khalif had taken intentional steps to become a member of the terror group.

It also found that the law accommodated the unstructured nature of such groups.

The High Court bench ultimately decided to uphold the original charges.

–ABC