Frenchman Mehdi Nemmouche, suspected of killing four people at Brussels' Jewish Museum in May, was remanded in custody for another three months on Friday, judicial officials said.
Nemmouche, 29, of Algerian origin and who spent more than a year fighting with Islamic extremists in Syria, has been charged with "murder in a terrorist context" after an Israeli couple, a French woman and a Belgian were shot dead at the museum in central Brussels.
The hearing took place in a closed session and officials said the remand period could be extended again, after Nemmouche was first ordered held for a month following his extradition from France at the end of July.
The court buildings in Brussels were under heavy security for the hearing, highlighting the sensitivity of the case which shocked the country and dismayed its Jewish community.
Nemmouche's lawyers said they had not asked for bail but that such an approach "was absolutely not an admission of guilt."
One of the lawyers, Sebastien Courtoy, said there was a major problem with prosecution in that "there is no direct proof of the clear presence of Nemmouche at the scene."
Courtoy claimed authorities were trying to blacken his client's character, citing recent press reports that Nemmouche had helped guard Western hostages held by Islamic extremists in Syria.
The museum shooting - the first such attack in Brussels in three decades - raised fears of a resurgence of anti-Semitic violence in Europe and of terror attacks from foreign fighters returning from Syria.
Nemmouche was arrested in the southern French city of Marseille days on from the attack after being spotted on a bus from Brussels.
A revolver and Kalashnikov rifle were found in his luggage, resembling weapons captured on museum security footage, as was a camera.
The museum is due to reopen to the public on Sunday amid tight security.
Museum officials said this week that Nemmouche does not want to take part in a reconstruction of the events there as part of the legal case against him.