That attack and a second at a Brussels metro station an hour later killed a total of 32 people and injured hundreds more.

Abrini was arrested in the Brussels neighbourhood of Anderlecht on Friday and, according to prosecutors, said he was the mystery “man in the hat” seen in surveillance footage next to the two bombers at the airport.

“He confessed his presence at the crime scene,” the federal prosecutor’s office said in a statement Saturday, adding that he also “explained having thrown away his vest (jacket) in a garbage bin and having sold his hat afterward”.

On Sunday, the office said that the terror group that struck Brussels initially planned to launch a second attack on France.

But the office said Sunday that the perpetrators were “surprised by the speed of the progress in the ongoing investigation” and decided to rush an attack on Brussels instead.

Even before the Brussels bombings, Abrini, 31, was a wanted man over his suspected role in the November 13 gun and suicide bomb attacks in Paris in which 130 people died.

The Belgian of Moroccan origin was seen at a petrol station north of Paris two days before the attacks with prime suspect Abdeslam, who drove one of the vehicles used in the attacks.

Belgian authorities have charged Abrini with “participation in the activities of a terrorist group and terrorist murders” over the massacres in the French capital.

During the course of the inquiry, it has emerged that Abrini has a long record of theft and drug possession, with his brother confirming he had done stints in jail.

“’Brioche’ is someone who likes money a lot and who has had a lot of money. In fact, he was reputed to have made himself 200,000 euros. That is a thief,” fellow suspect Ali Oulkadi told Belgian investigators.

“He never spoke about religion or anything like that.”

Identified as a radical Islamist by Belgian investigators, Abrini is believed to have briefly visited Syria last year and his younger brother Suleiman, 20, died there.

He was known to security services for belonging to the same cell as Abdelhamid Abaaoud, one of the organisers of the Paris attacks and one of the gunmen who opened fire on bars, restaurants and a concert hall there.

Abrini and Abdeslam - who was arrested near his family home in Molenbeek after a four-month manhunt - grew up together as teenage friends in the district, where they used to live next door to each other.

Belgian prosecutors said after Abrini’s arrest that he and Abdeslam had also rented an apartment in the Paris suburbs used by the November 13 gunmen before their deadly rampage.

The black Renault Clio the pair were driving was later used to transport the three suicide attackers who struck outside the Stade de France, and investigators believe Abrini accompanied Abdeslam and his brother Brahim - another attacker - on two other trips between Brussels and Paris.

Interviewed by AFP in November, Abrini’s family swore that on the night of the Paris bloodshed he was in Molenbeek, the tough, immigrant-heavy neighbourhood that has earned a reputation as a haven for radical jihadists.

His mother has said that he never spoke of going to Syria or of IS. “They say he is dangerous, that he is armed... It makes me sick,” she said.

His repeated trips between Paris and Brussels, however, suggested he played at least a logistical role in the tangled network of Islamic State militants behind two of the worst terror attacks on European soil in recent years.

Additional reporting by Associated Press