Eva Kaili asks a Belgian court to release her from detention under electronic surveillance.

A Greek MEP at the centre of a corruption scandal rocking the European Parliament has protested her innocence in a Belgian court, asking to be released from detention.

Eva Kaili, 44, was “cooperating in an active manner” with the Belgian federal prosecutor’s investigation and was requesting to be released under electronic surveillance, her lawyer, Andre Risopoulos, said outside the Brussels courtroom on Thursday.

The judge, who was only deciding custody terms and not weighing the case itself, was expected to give a decision later in the day.

Kaili, a former newsreader booted from her post as parliamentary vice president after police raids earlier this month, has become the face of the alleged corruption case.

Another of Kaili’s lawyers, Michalis Dimitrakopoulos, on Wednesday told reporters she feels miserable, “very troubled” and betrayed by her boyfriend and co-accused Francesco Giorgi.

“Things are difficult, but we have very strong legal arguments to set her free,” he said, arguing that Kaili is “not a flight risk and not in a position to destroy evidence”.

She was arrested on December 9 as Belgian police, searching a number of addresses, found 1.5 million euros ($1.6m) in cash. Kaili was charged shortly afterwards, and has been in detention since.

Another three suspects – her partner Giorgi; the head of an NGO allegedly used to funnel money; and a former MEP-turned-lobbyist, all of them Italian – were also arrested.

All four are charged with “criminal organisation, corruption and money laundering”.

A Belgian judge authorised Kaili’s arrest and detention on grounds she was allegedly caught red-handed with cash, meaning her usual parliamentary immunity could not be invoked.

Prosecutors said they had suspected for months that a Gulf state was trying to influence decisions in Brussels.

As various media outlets reported that Qatar was the Gulf state at the centre of the allegations, a Qatari official told Al Jazeera the country “categorically rejects any attempts to associate it with accusations of misconduct”.

The MEP denies receiving money from Qatar in exchange for influencing decisions affecting it in the EU parliament.

Thursday’s hearing took place behind closed doors.