Wheelchair-bound Osamah M. was sentenced to four years and eight months in prison in March 2016 by the Swiss Federal Criminal Court.
He was the supposed ringleader of a group believed to be trying to plant an Isis cell in Switzerland and carry out attacks in the country.
The Federal Supreme Court in March 2017 reduced his sentence by a year after an initial appeal.
Osamah M. then appealed again, arguing the criminal court had incorrectly classified his crimes as serious. He also said he had been the victim of a trial by media, adding that the large security presence outside the court during the original trial had given the impression he was guilty.
But in a recent ruling, the Federal Supreme Court rejected these arguments and upheld the reduced sentence of three years and eight months.
The court said the sentence handed to the Iraqi had been proportionate and was in line with federal law.
It also ruled that the Iraqi had failed to demonstrate to what extent intense media coverage had affected the case against him.
The Federal Supreme Court said there had been legitimate public interest in the case and the media had covered arguments put forward by defence lawyers.
The Lausanne-based court noted that intense media coverage of a case did not automatically mean a criminal sentence should be reduced – even if that coverage was at times sensationalist.
The argument that the security presence outside the court had prejudiced his trial was dismissed as irrelevant.
Osamah M. was released from jail in March 2017 after serving out his time. However, he cannot be deported to Iraq as he faces the death sentence there.
The man dubbed the “wheelchair bomber” by Swiss media arrived in Switzerland in 2012 and obtained asylum.
He is thought to have joined a terrorist organization in Iraq as early as 2004 and then posed as a victim of the Syrian civil war when applying for asylum in Switzerland.
Hospitalized in Schaffhausen in the north east of the country before being moved to a centre for paraplegics in the canton of Aargau, Osamah M. is said to have maintained close links with Isis and to have planned terrorist attacks.
Despite operations and rehabilitation, the Iraqi was active on social media platforms and posted videos supporting sharia law and terrorism.
The case, launched after a tip-off from foreign intelligence services, rested on the interpretations of communications between Osamah M. and three other men on Facebook and Skype, said Swiss news agency SDA at the time.
For the prosecution, the words they used – including one deemed a code for a bomb – indicated that they were trying to bring people and materials to Switzerland to prepare an attack.
The defence denied that interpretation with Osamah M. saying he felt he was under constant surveillance by the US.