Ms Kaili, 44, was one of four suspects arrested this month in relation to allegations of payments to influence decisions in the EU Parliament.
Qatari officials have insisted that the Gulf country has played no role in any wrongdoing.
Ms Kaili asked the custody hearing to grant her release under electronic surveillance and insisted on her innocence.
But the court ruled against her, ordering that she stay in detention for another month, the Belgium prosecutor's office said. Her lawyers can appeal against the decision.
Ms Kaili, a former newsreader, was sacked from her post as parliamentary vice president after police raids this month.
She was arrested on December 9 as Belgian police, searching a number of addresses, found €1.5 million ($1.6 million) in cash.
Ms Kaili was charged shortly afterwards and has been in detention since.
Another three suspects, all Italian — her partner Francesco Giorgi; the head of an NGO allegedly used to funnel money; and a former MEP-turned-lobbyist — were also arrested.
All four are charged with "criminal organisation, corruption and money laundering".
A Belgian judge authorised Ms Kaili's arrest and detention on grounds that she was allegedly caught with cash, meaning her usual parliamentary immunity could not be invoked.
Separate investigations have begun in Italy and Greece, and on Thursday Greek judicial sources said they had seized a 7,000-square-metre plot of land bought by Ms Kaili and Mr Giorgi on Paros, in the Cyclades islands, and frozen a bank account held by the couple.
Ms Kaili's hearing was conducted apart from the three other suspects, who appeared before a Belgian court on December 14.
On that date, the court ordered Mr Giorgi and the former MEP, Pier Antonio Panzeri, to remain in jail.
The NGO head, Niccolo Figa-Talamanca, was ordered to wear an electronic bracelet to track his movements, but that was suspended on appeal.
Ms Kaili's father was held in custody for two days after the police searches before being released.
Mr Panzeri's wife and daughter were arrested in Italy under a European warrant and could face extradition to Belgium in January to answer charges.