The International Committee for the Defence of Taysir Alluni said the court's decision came in response to repeated calls for a medical examination of the distinguished Aljazeera reporter, who suffers from several health problems.
The committee also singled out as a reason for the court's decision, the large turnout of participants at the first Media Symposium it organised in Madrid on 31 January 2005.
Many participants raised concerns about his health. Alluni has been known to suffer from heart ailments since 2001. He has also complained of chronic back problems.
"We not only urge the immediate release of Taysir Alluni for health reasons, we also believe he is innocent with regard to all the charges levelled against him," chief of Reporters Without Borders (RWF) Fernando Castillo told the gathering.
Castillo expressed his organisation's solidarity with Alluni and called for his release.
More than 100 Spanish, European and Arab intellectuals and media professionals attended the symposium.
They included representatives from RWF, Human Right Watch (HRW), the International Federation of Journalists (IFJ), Amnesty International (AI), cadres from various TV stations and newspapers, envoys from the Jordanian Journalists Union and the National Union of Moroccan Journalists.
Meanwhile, the Palestinian Journalists' Bloc described the Spanish government's handling of Alluni's case as part of a plan for repressing press freedom and hounding honest journalists.
In a press release, a copy of which was received by Aljazeera, the bloc called upon human-rights and other organisations concerned with defending journalists to use all available legal means to urge the Spanish government to free Alluni.